KR0183416B1 - Synchronous semiconductor memory device and semiconductor integrated circuit - Google Patents

Abstract

The synchronous semiconductor memory device of the present invention includes a clock input circuit for receiving a system clock signal, shaping the system clock signal and outputting an internal clock signal, and the internal clock connected to the clock input circuit and output from the clock input circuit. A data output circuit for performing a data output operation in synchronism with a rising or falling timing of the signal, and a constant voltage having a voltage value connected to the clock input circuit for suppressing a change in the operation speed of the transistor with respect to a temperature change, And a constant voltage generating circuit for supplying the constant voltage as the power supply voltage to the clock input circuit.

Description

Synchronous Semiconductor Memory and Semiconductor Integrated Circuits

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor devices, and more particularly, to a synchronous semiconductor memory device and a semiconductor integrated circuit which operate in synchronization with a clock signal supplied from an external source.

Background Art Conventionally, known semiconductor devices operating in synchronization with externally supplied clock signals include a microprocessor device (MPU) and a synchronous dynamic random access memory (SDRAM).

1 illustrates a portion of an electronic device using MPU and SDRAM. The MPU 1 and the SDRAM 2 are connected via the clock signal supply line 3 and the data bus 4, and the clock signal supply line 3 supplies the clock signal CLK to the MPU 1 and the SDRAM 2. In turn, the data bus 4 forms a transmission line for the data DQ. The MPU 1 has a clock signal input terminal 5 and a data input / output terminal 7, and the SDRAM 2 has a clock signal input terminal 6 and a data input / output terminal 8.

FIG. 2 is a timing diagram for explaining the operation of the electronic device shown in FIG. 1 when the SDRAM 2 outputs data. In Fig. 2, the clock signal CLK has a cycle time t _CLK of 10 ns, and the data DQ is data output from the SDRAM 2.

This SDRAM 2 has a clock signal access time t _CLKA of 6 ns and an output holding time t _OH of 2 ns. The clock signal access time t _CLKA is a delay time from when the rise of the clock signal CLK starts until the data DQ is output. On the other hand, the output holding time t _OH is a time from when the clock signal CKL rises to when the holding of the output data DQ ends.

Therefore, in this case, the cycle time t _CLK of the clock signal CLK is 10 ns and the data transfer rate is 100 MHz, but the setup time t _su can be set to 4 ns. This setup time t _su is the time when the data DQ is predetermined before the rise of the clock signal CLK.

However, according to the SDRAM 2 described above, the setup time t _su is shortened when the cycle time t _CLK of the clock signal CLK is shorter than 10 ns. Moreover, in some cases, a sufficiently long setup time t _su cannot be guaranteed.

For example, Fig. 20 is a timing diagram showing a case where the cycle time t _CLK of the clock signal CLK is set to 6 ns and the data transfer rate is 167 MHz. In this case, the setup time t _su cannot be guaranteed at all. In this manner, at the receiving end such as the MPU 1 shown in FIG. 1, the data DQ output from the SDRAM 2 cannot be input.

In this case, when controlling the output timing of the data DQ, the difference between the cycle time of the clock signal CLK t _CLK as a set-up time t _su on a clock signal CLK cycle time t output data even when _CLK is different from that in a predetermined range Consider incorporating a phase locked loop (PLL) circuit to ensure the same amount of time.

However, since the power consumption of the PLL circuit is large, it is inappropriate to use the PLL circuit in a semiconductor device such as the SDRAM 2, which needs to minimize the power consumption.

Accordingly, an overall object of the present invention is to provide a novel useful semiconductor device that can solve the above-mentioned problems.

1 is a system block diagram showing an example of a conventional electronic device.

Fig. 2 is a timing chart for explaining the operation of the electronic device when the SDRAM outputs data.

Fig. 3 is a timing chart for explaining the operation of the electronic device when the cycle time of the clock signal is short and the SDRAM outputs data.

Fig. 4 is a system block diagram showing the main parts of the first embodiment of the semiconductor device according to the present invention.

Fig. 5 is a circuit diagram showing a data output circuit control circuit of the first embodiment.

6 is a circuit diagram showing a single yarn pulse generating circuit.

7 is a circuit diagram showing a delay circuit.

8 is a circuit diagram showing a latch circuit.

9 is a circuit diagram showing a data output circuit.

Fig. 10 is a circuit diagram for explaining the operation of the data output circuit.

Fig. 11 is a circuit diagram for explaining the operation of the data output circuit.

Fig. 12 is a timing chart for explaining the operation of the first embodiment when outputting data.

Fig. 13 is a timing chart for explaining the operation of the first embodiment when outputting data.

14A to 14F are timing charts for explaining the operation of the first embodiment when outputting data, respectively.

Fig. 15 is a circuit diagram showing a data output circuit control circuit of the second embodiment of the semiconductor device according to the present invention.

Fig. 16 is a circuit diagram showing a data output circuit control circuit for explaining the operation of the second embodiment.

Fig. 17 is a timing chart for explaining the operation of the second embodiment when outputting data.

Fig. 18 is a circuit diagram showing a data output circuit control circuit for explaining the operation of the second embodiment.

Fig. 19 is a circuit diagram showing a data output circuit control circuit of the third embodiment of the semiconductor device according to the present invention.

20 is a circuit diagram showing a delay circuit.

Fig. 21 is a circuit diagram showing a part of the SDRAM.

Fig. 22 is a circuit diagram showing an input circuit of the SDRAM.

Fig. 23 is a circuit diagram showing part of the fourth embodiment of semiconductor device according to the present invention.

Fig. 24 is a circuit diagram showing an input circuit of the fourth embodiment.

Fig. 25 is a timing chart for explaining the operation of the fourth embodiment.

Fig. 26 is a circuit diagram showing part of the fifth embodiment of semiconductor device according to the present invention.

Fig. 27 is a circuit diagram showing part of the sixth embodiment of semiconductor device according to the present invention.

Fig. 28 is a circuit diagram showing a 1 bit memory circuit.

Fig. 29 is a circuit diagram for explaining the operation of a 1-bit memory circuit.

30 is a circuit diagram for explaining the operation of a 1-bit memory circuit.

Fig. 31 is a timing chart for explaining input timing of a chip select signal when an active command is input.

32 is a circuit diagram showing a 1-bit memory circuit of the seventh embodiment of the semiconductor device according to the present invention.

FIG. 33 is a circuit diagram showing another configuration of the input circuit shown in FIG.

34 is a system block diagram for explaining the operation principle of the eighth embodiment of the semiconductor device according to the present invention.

35 is a system block diagram showing the eighth embodiment of the semiconductor device according to the present invention.

36 is a circuit diagram showing an input circuit.

Fig. 37 is a circuit diagram for explaining the operation of the input circuit during normal operation.

Fig. 38 is a circuit diagram for explaining the operation of the input circuit during normal operation.

Fig. 39 is a circuit diagram for explaining the operation of the input circuit during the burn-in test.

40 is a circuit diagram for explaining the operation of the input circuit during the burn-in test.

Fig. 41 is a system block diagram showing a part of the SDRAM.

FIG. 42 is a timing chart for explaining a read operation of the SDRAM shown in FIG. 41;

43 is a system block diagram for explaining the operation principle of the ninth embodiment of semiconductor device according to the present invention.

44 is a system block diagram showing the main parts of a ninth embodiment of the semiconductor device.

45 is a circuit diagram showing a constant voltage generating circuit.

46 is a diagram showing the characteristics of the constant voltage generation circuit.

Fig. 47 is a circuit diagram showing a clock input circuit.

48 is a circuit diagram for explaining the operation of the clock input circuit.

Fig. 49 is a circuit diagram for explaining the operation of the clock input circuit.

50 is a circuit diagram showing a data output circuit.

Fig. 51 is a circuit diagram for explaining the operation of the data output circuit.

Fig. 52 is a circuit diagram for explaining the operation of the data output circuit.

Fig. 53 is a circuit diagram for explaining the operation of the data output circuit.

Fig. 54 is a circuit diagram showing a clock input circuit of the SDRAM.

FIG. 55 is a diagram showing a simulation result for the clock input circuit shown in FIG. 54; FIG.

56 is a system block diagram showing a configuration of an SDRAM.

Fig. 57 is a circuit diagram showing a part of the tenth embodiment of semiconductor device according to the present invention.

58 is a diagram showing simulation results for the tenth embodiment.

Fig. 59 is a circuit diagram showing a part of the eleventh embodiment of semiconductor device according to the present invention.

60 is a diagram showing simulation results for the eleventh embodiment.

Fig. 61 is a circuit diagram showing part of the twelfth embodiment of semiconductor device according to the present invention.

Explanation of symbols for the main parts of the drawings

10: clock signal input terminal

11: data output circuit control circuit

12: data output circuit

15: single yarn pulse generating circuit

17: delay circuit

20: inverter

22: cycle time measurement circuit

41 to 46: latch circuit

59: internal clock signal generation circuit

76 to 81: increased nMOS transistor

According to a feature of the present invention, there is provided a semiconductor device for receiving a first clock signal having a cycle time, comprising: a single yarn pulse generating circuit for generating a single yarn pulse having a predetermined pulse width at a timing of rising or falling of the first clock signal; ; A delay circuit connected to the single yarn pulse generating circuit and delaying the single yarn pulse to generate a plurality of delayed pulse signals, the cycle of the first clock signal being compared with the timing of the single yarn pulse and the timing of the delayed pulse signal; A cycle time measuring circuit for measuring time; A cycle time of the first clock signal connected to the cycle time measuring circuit and the single yarn pulse generating circuit, based on the cycle time measured by the cycle time measuring circuit and the single yarn pulse output from the single yarn pulse generating circuit; An internal clock generation circuit having a second second cycle time and generating a second clock signal having a rise or fall time dependent on the cycle time; Provided is a semiconductor device connected to the internal clock generation circuit and including a data output circuit for outputting data after a predetermined delay time from a rise or fall time of the second clock signal. According to the semiconductor device of the present invention, the cycle time of the external clock signal is measured using a delay circuit. In addition, an internal clock signal having the same cycle time as the external clock signal and having a rise or fall time that is ahead of the [predetermined time]-[the cycle time of the external clock signal] relative to the external clock signal is supplied to the data output circuit. As a result, even when the cycle time of the external clock signal is different, the same setup time can be ensured as long as the cycle time difference is within a predetermined range. Thus, the present invention can be applied to electronic equipment having different data transfer rates and circuit design becomes more free.

According to another aspect of the present invention, in a synchronous semiconductor memory device in which an address signal and a control signal are input in synchronization with a clock signal, a differential amplifier circuit is provided for each bit of the control signal and the address signal other than the chip select signal, respectively. A plurality of input circuits each having a plurality of input circuits each controlled in one of an active state and an inactive state in response to an activation signal; An activation circuit connected to the input circuit and outputting the activation signal to the differential amplifying circuit, the activation signal being changed in level depending on the level change of the chip select signal and transitioning to an active level when the chip select signal transitions to an active level; A synchronous semiconductor memory device is provided. According to the synchronous semiconductor memory device of the present invention, an input circuit provided for a signal other than the chip select signal has a high level after the predetermined delay time has elapsed since the level of the chip select signal is low. It becomes active only for a period from time to a predetermined delay time. That is, an input circuit provided for a signal other than the chip select signal becomes active only for a time that is equal to or nearly equal to the time when the chip select signal is active. Input circuits provided for signals other than the chip select signal become inactive for other times. As a result, since the input circuit provided for signals other than the chip select signal is not always active, the power consumption of the input circuit portion can be effectively reduced.

According to still another aspect of the present invention, in a synchronous semiconductor memory device in which an address signal and a control signal are input in synchronization with a clock signal, a differential amplifier circuit is provided for each bit of the control signal and the address signal other than the chip select signal, respectively. A plurality of input circuits each having: a plurality of input circuits each of which is controlled in one of an active state and an inactive state in response to an activation signal; Outputs the activation signal to the differential amplifier circuit, which is connected to the input circuit and which changes level depending on the level change of the chip select signal and transitions to an active level when the chip select signal transitions to an active level, or A synchronous semiconductor memory device having an activation circuit for outputting an activation signal having a level to the differential amplifier circuit is provided. According to the synchronous semiconductor memory device of the present invention, an input circuit provided for a signal other than the chip select signal has a high level after the predetermined delay time has elapsed since the level of the chip select signal is low. It becomes active only for a period from time to a predetermined delay time. That is, an input circuit provided for a signal other than the chip select signal becomes active only for a time that is equal to or nearly equal to the time when the chip select signal is active. Input circuits provided for signals other than the chip select signal become inactive for other times. As a result, since the input circuit provided for signals other than the chip select signal is not always active, the power consumption of the input circuit portion can be effectively reduced.

According to still another aspect of the present invention, in a synchronous semiconductor memory device in which an address signal and a control signal are input in synchronization with a clock signal, a differential amplifier circuit is provided for each bit of the control signal and the address signal other than the chip select signal, respectively. A plurality of input circuits each having: a plurality of input circuits each of which is controlled in one of an active state and an inactive state in response to an activation signal; It is connected to the input circuit and changes in level depending on the level change of the chip select signal until an activation command for instructing activation of a memory cell region is input and transitions to an active level when the chip select signal transitions to an active level. Outputs the activation signal to the differential amplifier circuit, and after the activation command is input, an activation signal having an active level is input to the differential amplifier circuit until a precharge command indicating a precharge of a memory cell region is input. A synchronous semiconductor memory device having an activation circuit for outputting is provided. According to the synchronous semiconductor memory device of the present invention, the differential amplifier circuit forming the ultra short circuit of the input circuit provided for a signal other than the chip select signal has a precharge from when the chip select signal transitions to a low level when an active command is input. It remains active only for the time until the command is entered. The differential amplifier circuit forming the ultrashort circuit of the input circuit provided for signals other than the chip select signal becomes inactive for another time. As a result, the differential amplifier circuit forming the ultrashort circuit of the input circuit provided for signals other than the chip select signal is not always active, which can effectively reduce the power consumption of the input circuit portion.

According to still another aspect of the present invention, there is provided a semiconductor device, comprising: a first input circuit for amplifying a clock signal; A second input circuit for amplifying the information signal; A latch circuit connected to the first input circuit and the second input circuit, the latch circuit latching the information signal output from the second input circuit at a rising or falling timing of the clock signal output from the first input circuit; The first input circuit includes a first threshold logic circuit to which the clock signal is supplied; The clock signal is supplied and has a high level threshold higher than the threshold of the first threshold logic circuit and a low level threshold lower than the threshold of the first threshold logic circuit, during normal operation of the semiconductor integrated circuit. A second threshold logic circuit inactive and active during the burn-in test; A first selection for selectively outputting a clock signal output from the first threshold logic circuit to the latch circuit during normal operation, and selectively outputting a clock signal output from the second threshold logic circuit to the latch circuit during burn-in test A semiconductor integrated circuit is provided that includes a circuit. According to the semiconductor integrated circuit of the present invention, even when noise is mixed into the rising or falling waveform of the clock signal during the burn-in test, the present embodiment can prevent the malfunction and execute the burn-in test in the usual manner. Moreover, in this embodiment, the input circuit provided for the information signal such as the chip select signal has the same configuration as the input circuit provided for the clock signal. For this reason, even when noise is mixed in the information signal, malfunction can be prevented and burn-in test can be performed in a conventional manner.

According to still another aspect of the present invention, there is provided a clock input circuit comprising: a clock input circuit configured to input a system clock signal and to form an internal clock signal by shaping the system clock signal; A data output circuit connected to said clock input circuit and performing a data output operation in synchronization with the rising or falling timing of said internal clock signal output from said clock input circuit; A constant voltage generating circuit connected to said clock input circuit, generating a constant voltage having a voltage value for suppressing a change in the operating speed of a transistor with respect to a temperature change, and supplying said constant voltage as said power supply voltage to said clock input circuit; A synchronous semiconductor memory device is provided. According to the synchronous semiconductor memory device of the present invention, data is output with a delay amount corresponding to an access time from a system clock signal. However, the clock input circuit is supplied with a constant voltage having a voltage value for suppressing the change in the operating speed of the transistor according to the temperature change. For this reason, it is possible to prevent the change in the delay time of the clock input circuit due to the change in the externally supplied power supply voltage and the temperature change. In addition, a constant voltage can be supplied as a power supply voltage to a circuit portion of an output transistor circuit composed of a data output circuit and an output transistor other than the level shift circuit. Therefore, it is possible to prevent the change in the delay time of the data output circuit due to the change in the power supply voltage and the temperature change supplied from the outside. In addition, since the change in the access time from the system clock signal due to the change in the supply voltage and the temperature supplied from the outside can be prevented, accurate data can be input to the destination of the data transfer.

According to still another aspect of the present invention, there is provided a current mirror circuit having three pairs of current input stages and current output stages; A first constant current source having a current input end and a current output end, a first end connected to one of the current input end and the current output end of the first constant current source, and a second end connected to the first end and the second end of the current mirror circuit, respectively First and second field effect transistors having stages, wherein the first and second stages of the current mirror circuit are two input terminals or two output terminals of the current mirror circuit, and the second field effect transistor has a reference potential. A differential amplifier circuit having a gate supplied thereto; A third constant current source having a current input end and a current output end, a third end having a first end connected to one of the current input end and the current output end of the second constant current source and a second end connected to the third end of the current mirror circuit; A field effect transistor, said third end of said current mirror circuit having an input end circuit that is an input end or an output end of said current mirror circuit other than the first end and said second end of said current mirror circuit; A semiconductor integrated circuit is provided in which an output signal corresponding to an amplified signal of an input signal supplied to a gate of an effect transistor is output from a second end of one of the first and second field effect transistors. According to the semiconductor integrated circuit of the present invention, the signal propagation delay time can be shortened and the increase of the chip area can be suppressed only by adding a field effect transistor.

According to still another aspect of the present invention, there is provided an electronic device comprising: a current mirror circuit having two pairs of current input and output ends; A first constant current source having a current input end and a current output end, a first end connected to one of the current input end and the current output end of the first constant current source, and a second end connected to the first end and the second end of the current mirror circuit, respectively First and second field effect transistors having stages, wherein the first and second stages of the current mirror circuit are two input terminals or two output terminals of the current mirror circuit and are referenced to a gate of the second field effect transistor. A differential amplifier circuit to which a potential is supplied; A second constant current source having a current input stage and a current output stage, a load field effect transistor, a first stage connected to one of the current input stage and the current output stage of the second constant current source, a gate of the first field effect transistor, and the load field A third field effect transistor having a second end connected to one end of the effect transistor, the second end of the load field effect transistor having an input terminal circuit connected to a power supply line, and supplied to a gate of the third field effect transistor A semiconductor integrated circuit is provided in which an output signal corresponding to an amplified signal of an input signal to be output is output from a second stage of one of the first and second field effect transistors. According to the semiconductor integrated circuit of the present invention, the signal propagation delay time can be shortened and the increase of the chip area can be suppressed only by adding a field effect transistor.

Other objects and features of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

First, a first embodiment of a semiconductor device according to the present invention will be described with reference to FIGS.

Fig. 4 shows the main part of the first embodiment. The semiconductor device shown in FIG. 4 includes a data output circuit control circuit 11 and a data output circuit 12. The clock signal CLK is externally input to the clock signal input terminal 10, and the data output circuit control circuit 11 generates the internal clock signal INT-CLK based on the clock signal CLK. The data output circuit control circuit 11 controls the data output circuit 12. The data output circuit 12 starts an operation of outputting the data DQ in synchronization with the rising timing of the internal clock signal INT-CLK supplied from the data output circuit control circuit 11. The data DQ is output through the data output terminal 13.

In this embodiment, the data output circuit control circuit 11 has the configuration shown in FIG. The data output circuit control circuit 11 includes a single yarn pulse generating circuit 15, a cycle time measuring circuit 22, and an internal clock signal generating circuit 59. The single yarn pulse generator circuit 15 generates a single yarn pulse having a pulse width of 1 ns.

6 shows the configuration of the single yarn pulse generator circuit 15. As shown in FIG. In Fig. 6, the single yarn pulse generation circuit 15 includes a delay circuit 17, a NAND circuit 19 and an inverter 20. Delay circuit 17 causes an inverter _{(18 1 ~18 2m-1)} ( where, m is an integer), and delaying the clock signal CLK. The NAND circuit 19 obtains a NAND operation between the clock signal and the output of the delay circuit 17, and the inverter 20 inverts the output of the NAND circuit 19.

In FIG. 5, the cycle time measuring circuit 22 measures the cycle time of the clock signal CLK via a single yarn pulse output from the single yarn pulse generator circuit 15. In FIG. The cycle time measuring circuit 22 includes delay circuits 23 to 32, AND circuits 35 to 40, and latch circuits 41 to 46, which are connected as shown in FIG.

The delay circuits 23 to 32 each have a delay time of 1 ns. The delay circuits 23 to 32 may have the same circuit configuration. For example, the delay circuit 23 has the configuration shown in FIG. In Fig. 7, the delay circuit 23 includes inverters 33 _{1 to} 33 _2n , where n is an integer.

In Fig. 5, the AND circuits 35 to 40 obtain an AND operation with the corresponding one of the clock signal CLK and the outputs of the delay circuits 27 to 32, respectively.

In addition, the latch circuits 41 to 46 form a cycle time memory circuit for storing the measurement result, that is, the cycle time of the clock signal CLK. The latch circuits 41 to 46 can have the same circuit configuration. For example, the latch circuit 41 has the configuration shown in FIG. In Fig. 8, the latch circuit 41 includes an OR circuit 48, an AND circuit 49, an inverter 50, a clock signaling inverter 51 connected as shown, and a latch circuit 56 connected as shown. It includes. The clock signaling inverter 51 includes incremental p-channel metal oxide semiconductor transistors (pMOS transistors) 52 and 53 and incremental n-channel MOS transistors (nMOS transistors) 54 and 55. Latch circuit 56 latches the output of clock signaling inverter 51 and includes inverters 57 and 58.

In Fig. 5, the internal clock signal generation circuit 59 uses the internal clock signal INT based on the output of the latch circuits 41 to 46 which store the cycle time of the clock signal, and the single yarn pulse output from the single yarn pulse generation circuit 15. Generate a CLK. The internal clock signal generation circuit 59 shown in FIG. 5 includes delay circuits 60 to 69, AND circuits 70 to 75, incremental nMOS transistors 76 to 81, inverters 82, and the like connected as shown. Resistor 83. The delay circuits 60 to 69 each have a delay time of 1 ns and have the same circuit configuration as the delay circuits 23 to 32. The on / off states of the incremental nMOS transistors 76-81 are controlled by the outputs of the corresponding AND circuits 70-75.

In this embodiment, the data output circuit 12 shown in FIG. 4 has a clock signal access time t _CLKA of 6 ns, and has the configuration shown in FIG. In Fig. 9, the data output circuit 12 includes a data register 85, inverters 86 and 87, a clock signaling inverter 88, a latch circuit 93 and an output circuit portion 96 connected as shown. do.

The data register 85 stores the data DQ to be output. Inverter 86 inverts the output of data register 85 and inverter 87 inverts the internal clock signal INT-CLK. Clock signaling inverter 88 includes incremental pMOS transistors 89 and 90 and incremental nMOS transistors 91 and 92. Latch circuit 93 latches the output of clock signaling inverter 88 and includes inverters 94 and 95. The output circuit 96 includes an incremental pMOS transistor 97 forming a pull-up element and an incremental nMOS transistor 98 forming a pull-down element.

In the data output circuit 12, the pMOS transistor 89 and the nMOS transistor 91 are turned on when the internal clock signal INT-CLK is at a high level as shown in FIG. In FIG. 10 and subsequent figures, H denotes the high level of the signal, and L denotes the low level of the signal. When the output of the data register 85 is at the high level, the output level of the inverter 86 is turned low, the pMOS transistor 89 is turned on, and the nMOS transistor 92 is turned off. As a result, the output level of the clock signaling inverter 88 goes low, the pMOS transistor 97 turns on, the nMOS transistor 98 turns off, and the level of the output data DQ goes high.

On the other hand, when the output level of the data register 85 is low as shown in FIG. 11, the output level of the inverter 86 becomes high, the pMOS transistor 89 is turned off, and the nMOS transistor 92 It is turned on. As a result, the output level of the clock signaling inverter 88 goes low, the output level of the latch circuit 93 goes high, the pMOS transistor 97 turns off, the nMOS transistor 98 turns on, The level of the output data DQ goes low.

In addition, when the level of the internal clock signal INT-CLK is low, the pMOS transistor 90 and the nMOS transistor 91 are turned off, and the output state of the clock signaling inverter 88 is in a high impedance state, and the latch circuit ( 93 maintains the data DQ of the previous cycle.

Fig. 12 is a timing chart for explaining the operation of this embodiment when outputting data when the cycle time t _CLK of the clock signal CLK is 10 ns and the data transfer rate is 100 MHz. Fig. 12 shows the timings of the clock signal CLK, the signals or potentials at the nodes N1 to N24, the internal clock signal INT-CLK and the data DQ.

The single yarn pulse generation circuit 15 detects the rising timing of the clock signal CLK and generates a pulse having a pulse width of 1 ns. Therefore, the output of the single yarn pulse generating circuit 15, i.e., the potential at the node N1 shown in FIG. 5 becomes as shown by N1 in FIG.

The delay circuits 23 to 32 each have a delay time of 1 ns. Therefore, the outputs of the delay circuits 23 to 32, i.e., the potentials at the nodes N2 to N7 shown in FIG. 5, are as shown by N2 to N7 in FIG.

As a result, the outputs of the AND circuits 35 to 39, i.e., the potentials at the nodes N8 to N12 shown in FIG. 5, are always low as shown by N8 to N12 in FIG. Thus, the output of the AND circuit 40, i.e., the potential at node N13 shown in FIG. 5, changes similarly to the potential at node N7 as shown by N13 in FIG.

The latch circuits 41 to 45 latch the low level outputs of the corresponding AND circuits 35 to 39. Therefore, the outputs of the latch circuits 41 to 45, i.e., the potentials at the nodes N14 to N18 shown in Fig. 5, always have a low level, as shown in Figs.

On the other hand, the latch circuit 46 latches the high level output of the AND circuit 40. Therefore, the output of the latch circuit 46, i.e., the potential at the node N19 shown in FIG. 5, always has a high level as indicated by N19 in FIG.

The delay circuits 60 to 69 each have a delay time of 1 ns. Thus, the outputs of the delay circuits 61, 63, 65, 67, and 69, i.e., the potentials at the nodes N20 to N24 shown in Fig. 5 are as indicated by N20 to N24 in Fig. 12, respectively.

As a result, the outputs of the AND circuits 70-74 always have a low level, and the nMOS transistors 76-80 are always off.

On the other hand, the output of the AND circuit 75 changes similar to the output of the delay circuit 69. Therefore, the nMOS transistor 81 repeats the on / off state in synchronization with the output of the AND circuit 75.

Thus, if the clock signal CLK cycle time of 10ns t _CLK, a signal similar to the output of the delay circuit 69 is output as the internal clock signal CLK-INT as shown in Fig. This internal clock signal INT-CLK has the same cycle time as the clock signal CLK. In addition, this internal clock signal INT-CLK has a rising timing that is advanced by [10 ns predetermined time]-[cycle time t _CLK = 10 ns] = 0 ns of the clock signal CLK. That is, the rise timing of the internal clock signal INT-CLK is the same as the rise timing of the clock signal CLK.

Since the clock signal access time t _CLKA of the data output circuit 12 is 6 ns, 4 ns can be secured as the setup time t _SU .

Fig. 13 is a timing chart illustrating the operation of this embodiment when outputting data when the cycle time t _CLK of the clock signal CLK is 8 ns and the data transfer rate is 125 MHz. Fig. 13 shows the timing of the clock signal CLK, the signals or potentials at the nodes N1 to N24, the internal clock signal INT-CLK, and the data DQ.

The single yarn pulse generating circuit 15 detects the rising timing of the clock signal CLK and generates a pulse having a pulse width of 1 ns. Therefore, the output of the single yarn pulse generating circuit 15, i.e., the potential at the node N1 shown in FIG. 5 becomes as shown by N1 in FIG.

Each delay circuit 23 to 32 has a delay time of 1 ns. Therefore, the outputs of the delay circuits 23 to 32, i.e., the potentials at the nodes N2 to N7 shown in Fig. 5 are as shown as N2 to N7 in Fig. 13, respectively.

As a result, the outputs of the AND circuits 35 to 37, 39 and 40, i.e., the potentials at the nodes N8 to N10, N12 and N13 shown in FIG. 5, are shown as N8 to N10, N12 and N13 in FIG. It is always at the low level. Thus, the output of the AND circuit 38, i.e., the potential at node N11 shown in FIG. 5, changes similarly to the potential at node N5 as shown by node N11 in FIG.

The latch circuits 41 to 43, 45 and 46 latch the low level outputs of the corresponding AND circuits 35 to 37, 39 and 40. Therefore, the outputs of the latch circuits 41 to 43, 45 and 46, i.e., the potentials at the nodes N14 to N16, N18 and N19 shown in Fig. 5 are always as shown in Fig. 13 as N14 to N16, N18 and N19. Has a low level.

On the other hand, the latch circuit 44 latches the high level output of the AND circuit 38. Therefore, the output of the latch circuit 44, i.e., the potential at the node N17 shown in FIG. 5, always has a high level as shown by N17 in FIG.

The delay circuits 60 to 69 each have a delay time of 1 ns. Thus, the outputs of the delay circuits 61, 63, 65, 66 to 69, i.e., the potentials at the nodes N20 to N24 shown in Fig. 5 are shown as nodes N20 to N24 in Fig. 13, respectively.

As a result, the outputs of the AND circuits 70-72, 74, 75 always have a low level, and the nMOS transistors 76-78, 80, 81 are always off.

On the other hand, the output of the AND circuit 73 changes similarly to the output of the delay circuit 65. Therefore, the nMOS transistor 79 repeats the on / off state in synchronization with the output of the AND circuit 73.

Therefore, when the cycle time of the clock signal CLK is 8ns t _CLK, a signal similar to the output of the delay circuit 65 is output as the internal clock signal CLK-INT as shown in Fig. This internal clock signal INT-CLK has the same cycle time as the clock signal CLK. The internal clock signal INT-CLK also has a rising timing that is ahead of the clock signal CLK by [the predetermined time of 10 ns]-[the cycle time t _CLK = 8 ns] = 2 ns of the clock signal CLK.

Since the clock signal access time t _CLKA of the data output circuit 12 is 6 ns, 4 ns can be secured as the setup time t _su .

14A, 14B, 14C, 14D, 14E and 14F show the clock signal CLK and the internal clock signal for the case where the cycle time t _CLK of the clock signal _CLK is 10ns, 9ns, 8ns, 7ns, 6ns and 5ns, respectively. A timing chart showing the relationship between INT-CLK and output data DQ.

Therefore, according to the first embodiment of the present invention, the data output circuit 12 outputs the data DQ after the clock signal access time t _CLKA of 6 ns from the rising timing of the internal clock signal INT-CLK. However, the internal clock signal INT-CLK has the same cycle time as the clock signal CLK, and the rise time of the internal clock signal INT-CLK is [the predetermined time of 10 ns]-[the cycle time t _CLK of the clock signal CLK] compared to the clock signal CLK. ] Ahead.

As a result, when the clock signal CLK cycle time t _CLK of 10ns, 9ns, 8ns, 7ns, 6ns and 5ns, the timing at which the data DQ outputted from the data output circuit 12 are the same as seen from the rising of the next clock signal CLK It becomes possible to fix the setup time t _su of 4ns.

Therefore, the first embodiment can be applied to a transmission device having data transmission rates of 100 MHz, 111 MHz, 125 MHz, 143 MHz, 167 MHz, and 200 MHz, and the flexibility of circuit design is improved.

Next, a second embodiment of the semiconductor device according to the present invention will be described with reference to FIGS. 15 to 18. FIG.

Fig. 15 shows the main parts of the second embodiment. More specifically, Fig. 15 shows a data output circuit control circuit of the second embodiment.

The second embodiment uses the data output circuit control circuit 11 shown in FIG. 15 instead of the data output circuit control circuit 11 shown in FIG. Except for this, the second embodiment is essentially the same as the first embodiment described above.

The data output circuit control circuit 11 shown in FIG. 15 is provided with a switching circuit 100. Except for this point, the data output circuit control circuit 11 shown in FIG. 15 is essentially the same as the data output circuit control circuit 11 shown in FIG. In FIG. 15, the same reference numerals are given to the same parts as the corresponding parts of FIG. 5, and the detailed description thereof is omitted.

In Fig. 15, the switching circuit 100 includes incremental nMOS transistors 101 to 106, resistors 107, inverters 108 and 109, AND circuits 110 and 111, and an OR circuit 112.

In the second embodiment, the level of one of the outputs of the latch circuits 41 to 46 becomes high when the cycle time t _CLK of the clock signal _CLK becomes one of 10 ns, 9 ns, 8 ns, 7 ns, 6 ns, and 5 ns. do.

As a result, as shown in FIG. 16, the input level of the inverter 108 becomes low, the output level of the inverter 108 becomes high, the output level of the inverter 109 becomes low, and the AND circuit ( The output level of 111 is fixed at the low level.

In this case, therefore, the AND circuit 110 operates as a non-inverting circuit with respect to the output of the inverter 82, and the OR circuit 112 operates as a non-inverting circuit with respect to the output of the AND circuit 110. Therefore, the internal clock signal INT-CLK generated from the internal clock signal generation circuit 59 is supplied to the data output circuit 12.

On the other hand, if the cycle time of the clock signal CLK when the _CLK t 10ns later, that is, for example, 12ns, output level of the latch circuits (41 to 46) are all low. In other words, the potentials at the nodes N14 to N19 are all low as shown by N14 to N18 and N19 in FIG. Fig. 17 is a timing chart illustrating the operation of this embodiment when outputting data when the cycle time t _CLK of the clock signal CLK is 12 ns. 17 shows the clock signal CLK, the signals or potentials at the nodes N1 to N24, and the timing of the internal clock signal INT-CLK.

As a result, as shown in Fig. 18, the nMOS transistors 76 to 81 are turned off, the nMOS transistors 101 to 106 are turned off, and the input level of the inverter 82 becomes high, and the inverter ( The output level of 82 becomes low, the input level of inverter 108 goes high, the output level of inverter 108 goes low, and the output level of inverter 109 goes high.

Therefore, the output of the AND circuit 110 is fixed at a low level, the AND circuit 111 operates as a non-inverting circuit with respect to the single incident pulse output from the single yarn pulse generating circuit 15, and the OR circuit 112 is AND The output of the circuit 111 operates as a non-inverting circuit.

As a result, in this case, a single yarn pulse output from the single yarn pulse generator circuit 15, that is, a signal having the same cycle time and rising timing as the clock signal CLK, is supplied to the data output circuit 12.

Therefore, the second embodiment can be applied to electronic devices having data transmission rates of 100 MHz, 111 MHz, 125 MHz, 143 MHz, 167 MHz, 200 MHz, and 100 MHz or less, and the flexibility of circuit design is improved.

Next, a third embodiment of the semiconductor device according to the present invention will be described with reference to FIGS. 19 and 20. FIG.

Fig. 19 shows the main part of the third embodiment. More specifically, Fig. 19 shows the data output circuit control circuit of the third embodiment.

The third embodiment uses the data output circuit control circuit 11 shown in FIG. 19 instead of the data output circuit control circuit 11 shown in FIG. Except for this point, the third embodiment is essentially the same as the above-described second embodiment.

The data output circuit control circuit 11 shown in FIG. 19 is provided with a cycle time measuring circuit 114 having the configuration shown in place of the cycle time measuring circuit 22. Except for this point, the data output circuit control circuit 11 shown in FIG. 19 is essentially the same as the data output circuit control circuit 11 shown in FIG. In FIG. 19, the same reference numerals are given to the same parts as the corresponding parts of FIG. 15, and detailed description thereof will be omitted.

The cycle time measuring circuit 114 has a delay circuit 115 to 119 having a circuit configuration different from that of the delay time 23 to 27 of the cycle time measuring circuit 22 shown in FIG. 15 instead of the delay circuits 23 to 27. It is provided. In addition, the cycle time measuring circuit 114 is provided with an AND circuit 120 to 125, and a programmable data storage circuit 126 for controlling the delay circuits 115 to 119 and the AND circuits 120 to 125.

The delay circuits 115 to 119 may have the same circuit configuration. For example, the delay circuit 115 has the configuration shown in FIG. The delay circuit 115 shown in FIG. 20 includes a delay circuit 128, AND circuits 130 and 131 and an OR circuit 132. Delay circuit 128 includes inverters 129 _{1 to} 129 _2k , where k is an integer. The programmable data PD is supplied to the AND circuits 130 and 131 from the programmable data storage circuit 126 shown in FIG.

When the programmable data PD has a high level, the output of the AND circuit 130 is fixed at a low level, and the AND circuit 131 operates as a non-inverting circuit with respect to the output of the delay circuit 128, in which case the delay The output of the circuit 128 is fed to the circuit of the next stage.

On the other hand, when the programmable data PD has a low level, the output of the AND circuit 131 is fixed at the low level, and the AND circuit 130 operates as a non-inverting circuit with respect to the input signal of the AND circuit 130. In this case, the input signal is supplied as is to the circuit of the next stage.

In the third embodiment, the delay time on the delay circuits 115 to 119 is a test performed at the wafer stage to select the delay circuit to be used and to fix the output of the required circuit among the AND circuits 120 to 125 at a low level, that is, Measured by a wafer probing test.

Therefore, the third embodiment can be applied to electronic devices having data transmission rates of 100 MHz, 111 MHz, 125 MHz, 143 MHz, 167 MHz, 200 MHz and 100 MHz or less, and the flexibility of circuit design is further improved compared with the first embodiment. In addition, it becomes possible to perform timing on the delay circuits 115 to 119.

According to the first to third embodiments described above, the cycle time of the external clock signal is measured using a delay circuit. In addition, an internal clock signal having the same cycle time as the external clock signal and having a rising or falling timing that is ahead of the [predetermined time]-[the cycle time of the external clock signal] relative to the external clock signal is supplied to the data output circuit. As a result, even when the cycle time of the external clock signal is different, it is possible to ensure the same setup time if the difference in the cycle time is within a predetermined range. Therefore, the present invention can be applied to electronic devices having different data transfer rates, and the flexibility of circuit design can be improved.

FIG. 21 shows the configuration of the SDRAM 2 shown in FIG. The SDRAM 2 is an example of a synchronous semiconductor memory device in which a control signal and an address signal supplied from the outside are also input in synchronization with a clock signal supplied from the outside.

The SDRAM 2 shown in Fig. 21 is connected to the external input terminals 201 _{1 to} 201 _{m + 1} , the input circuits 202 _{1 to} 202 _m , and the latch circuits 203 _{1 to} 203 _{m-1 which are connected as shown.} ). Latch circuits (203 ₁ ~203 _m-1) in synchronization with the rising edge of the clock signal CLK outputted from the input circuit (202 ₁₎ and latches the signal outputted from the input circuit (202 ~202 _{m 2),} respectively.

The clock signal CLK is supplied to the clock signal input terminal 201 ₁ , and the chip select signal / CS is supplied to the chip select signal input terminal 201 ₂ . The row address strobe signal / RAS is supplied to the row address strobe signal input terminal 201 ₃ , and the column address strobe signal / CAS is supplied to the column address strobe signal input terminal 201 ₄ . The write enable signal / WE is supplied to the write enable signal input terminal 201 ₅ , and the output mask signal DQM is supplied to the output mask signal input terminal 201 ₆ . The most significant bit MSB of the address signal is supplied to the address signal input terminal 201 ₇ , and the least significant bit LSB A ₁ of the address signal is supplied to the address signal input terminal 201m. The reference voltage VREF is supplied to the reference voltage input terminal 201 _{m + 1} . For example, the reference voltage VREF is 1.5V.

The input circuits 202 _{1 to} 202 _m have the same circuit configuration. For example, the input circuit 202 ₁ has the configuration shown in FIG.

The input circuit 202 ₁ shown in Fig. 22 includes a differential amplifier circuit 204, for example, a VCC power supply line 205 for supplying a power supply voltage VCC of 3V and inverters 211 to 213. The differential amplification circuit 204 comprises an incremental pMOS transistor 206 and 207 forming a current mirror circuit and forming a load, an incremental nMOS transistor 208 and 209 forming a driving transistor and an incremental nMOS transistor 210 functioning as a resistance element. It includes. Inverters 211 to 213 are provided for shaping the waveform, and the output of the inverter 213 is connected to the clock signal input terminal of the latch circuits 203 to 203 _m-1 shown in FIG.

In the input circuit 202 ₁ shown in Fig. 22, when the clock signal CLK is at a high level, the nMOS transistor 208 is turned on, the nMOS transistor 209 is turned off, and the voltage at the node 214 is low. It becomes a level. As a result, the output level of the inverter 211 becomes high, the output level of the inverter 212 becomes low, the output level of the inverter 213 becomes high, and this high level of the inverter 213 The output is supplied to the clock signal input terminals of the latch circuits 203 _{1 to} 203 _m-1 .

On the other hand, when the clock signal CLK is at the low level, the nMOS transistor 208 is turned off, the nMOS transistor 209 is turned on, and the voltage at the node 214 is at a high level. As a result, the output level of the inverter 211 goes low, the output level of the inverter 212 goes high, the output level of the inverter 213 goes low, and this low level output of the inverter 213 latches. It is supplied to the clock signal input terminal of the circuits 203 _{1 to} 203 _m-1 .

In the differential amplifier circuit 204 forming the ultrashort circuit of the input circuit 202 ₁ , the gate of the nMOS transistor 210 functioning as a resistance element is connected to the VCC power supply line 205. Thus, the nMOS transistor 210 is constantly turned on, and current flows in the differential amplifier circuit 204 at all times.

In addition, the input circuits 202 _{1 to} 202 _m have the same circuit configuration. For this reason, the differential amplifier of the input circuit (202 ~202 _{m 2)} Each of the differential amplifier circuit 204, and has a differential amplifier circuit having the same circuit configuration, respective input circuits (202 ~202 _{m 2)} as a front-end circuit of the There is always a current through the circuit.

Therefore, according to the SDRAM 2 shown in Fig. 21, the electric power consumption increases because current always flows in the differential amplifier circuit forming the ultra short circuit of each input circuit 202 _{1 to} 202 _m .

Therefore, the fourth to seventh embodiments of the semiconductor device according to the present invention, in which power consumption of the input circuit portion can be reduced, will be described with reference to FIGS. 23 to 32. FIG. In the fourth to seventh embodiments, the present invention is applied to an SDRAM. Incidentally, the same reference numerals are given to the same parts as those in FIG. 21 in FIGS. 23, 26, and 27, and detailed description thereof will be omitted.

The fourth embodiment will be described with reference to Figs. Fig. 23 shows the construction of a part of the fourth embodiment. In the fourth embodiment, an inverter 219 is provided. Inverter 219 inverts the chip select signal / CS is outputted from the input circuit (202 ₂₎ provided relative to the chip select signal / CS, and outputs an activation signal Φ _E for operating the differential amplifier circuit.

Also, for the bits An to A ₁ of the address signal and the control signals / RAS, / CAS, / WE, and DQM other than the chip select signal / CS, the input circuits 202 _{3 to} 202 _m shown in FIG. instead, there is provided an input circuit (220 ₃ ~220 _m). The active / inactive state of the input circuits 220 _{3 to} 220 _m is controlled by the activation signal Φ _E output from the inverter 219.

The other part of the SDRAM 2 shown in FIG. 23 is the same as the SDRAM 2 shown in FIG.

The input circuits 220 _{3 to} 220 _m have the same circuit configuration. For example, the input circuit 220 ₃ has the configuration shown in FIG.

The input circuit 220 ₃ shown in Fig. 24 includes a differential amplifier circuit 221, a VCC power supply line 222 for supplying a power supply voltage VCC, and inverters 228 to 230. The differential amplification circuit 221 comprises an incremental pMOS transistor 223,224 forming a current mirror circuit and forming a load, an incremental nMOS transistor 225,226 forming a driving transistor, and an incremental nMOS transistor 227 functioning as a resistance element. It includes. The gate of the nMOS transistor 227 is connected to the output terminal of the inverter 219, on / off states of the nMOS transistor 227 is controlled by an enable signal Φ _E. An inverter (228-230) is provided for shaping a waveform and an output of the inverter 230 is connected to a row address strobe signal input terminal of the latch circuit (203 ₂₎ shown in Fig.

In the input circuit (220 _3), when the activation signal Φ _E is at the low level, nMOS transistor 227 is turned off the differential amplifier circuit 221 is inactive.

On the other hand, if enable signal Φ _E is at the high level, nMOS transistor 227 is turned on, and the differential amplifier circuit 221 is active.

In this case, when the row address strobe signal / RAS is at the high level, the nMOS transistor 225 is turned on, the nMOS transistor 226 is turned off, and the voltage at the node 231 indicates a low level. As a result, the output level of the inverter 228 becomes high, the output level of the inverter 229 becomes low, the output level of the inverter 230 becomes high, and the high level output of this inverter 230 latches. It is supplied to the row address strobe input terminal of the circuit 203 ₂ .

On the other hand, when the row address strobe signal / RAS is at the low level, the nMOS transistor 225 is turned off, the nMOS transistor 226 is turned on, and the voltage at the node 231 indicates a high level. As a result, the output level of the inverter 228 goes low, the output level of the inverter 229 goes high, the output level of the inverter 230 goes low, and the low level output of the inverter 230 latches. It is supplied to the row address strobe signal input terminal of the circuit 203 ₂ .

According to this embodiment, when the chip select signal / CS supplied from the outside is at a high level, the level of the chip select signal / CS output from the input circuit 202 ₂ is high, and the activation signal Φ _E is at a low level. The differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m represents an inactive state.

However, when the chip select signal / CS supplied from the outside is at a low level, the level of the chip select signal / CS output from the input circuit 202 ₂ becomes low, the activation signal Φ _E indicates a high level, and the input circuit A differential amplifier circuit forming an ultrashort circuit of (220 _{3 to} 220 _m ) exhibits an active state.

When the chip select signal / CS transitions from the high level to the low level, the activation signal Φ _E transitions from the low level to the high level after a delay of a predetermined time. Therefore, the timing of the chip select signal / CS must be determined in consideration of this predetermined time delay.

Fig. 25 is a timing chart for explaining the input timing of the chip select signal / CS. Fig. 25 shows timings of the clock signals CLK, the chip select signal / CS, the bits A _{n to} A ₁ of the address signal, and the control signals / RAS, / CAS and / WE other than the chip select signal / CS. .

That is, in this embodiment, for example, when the setup time t _SETUP required for the control signal and the address signal is 2 ns, the setup time t _SETUP-CS of the chip select signal / CS indicates that the chip select signal / CS transitions from the high level to the low level. After that, the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m should be set longer than the setup time t _SETUP in consideration of the time taken to become active.

In Fig. 25, the holding time t _HOLD required for the control signal and the address signal is, for example, 2 ns. The holding time t _HOLD is sufficient as the holding time of the chip select signal / CS.

Therefore, according to this embodiment, the input circuits 220 _{3 to} 220 _m have a time when the level of the chip select signal / CS becomes high after a predetermined delay time has elapsed since the level of the chip select signal / CS goes low. It becomes active only for a period from to until a predetermined delay time has elapsed. That is, the input circuits 220 _{3 to} 220 _m become active only for a time equal to or approximately equal to the time when the chip select signal / CS is active. Input circuitry (220 ₃ ~220 _m) becomes inactive during another time. As a result, since the input circuits 220 _{3 to} 220 _m are not always active, the power consumption of the input circuit portion can be effectively reduced.

A fifth embodiment of the semiconductor device according to the present invention will be described below with reference to FIG. Fig. 26 shows some configurations of the fifth embodiment. In this embodiment, the differential amplifier circuit activation circuit 233 is provided in place of the differential amplifier circuit activation circuit of the fourth embodiment including the inverter 219. The differential amplifier circuit activation circuit 233 has a configuration different from that of the fourth embodiment. Otherwise, the fifth embodiment is essentially the same as the above described fourth embodiment.

The differential amplifier circuit activation circuit 233 includes an inverter 234, a 1-bit memory circuit 235, and an OR circuit 236. Inverter 234 inverts the chip select signal / CS is outputted from the input circuit (202 ₂₎ provided for the chip select signal / CS. The 1-bit memory circuit 235 stores a high level or low level signal in response to a command signal composed of a control signal and an address signal, and outputs a stored high level or low level signal. OR circuit 36 calculates an OR operation of the outputs of the 1-bit memory circuit 35 of the inverter 34, and outputs an enable signal Φ _E.

When the output level of the 1-bit memory circuit 235 is low, the output of the inverter 234 is supplied as an activation signal Φ _E to the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m . Therefore, in this case, if the chip selection signal / CS is at a high level supplied from the outside, the input circuit (202 ₂₎ the chip select level of the signal / CS is output from being high, the output level of the inverter 234 is at a low and, the level of the activation signal Φ _E is low, the differential amplifier circuit forming the first stage circuit of the input circuit (220 ₃ ~220 _m) is in an inactive state.

On the other hand, when the chip selection signal / CS is at a low level supplied from the outside, input chip enable level of the signal / CS output from the circuit (202 ₂₎ is low, the output level of the inverter 234 is high, the activated The level of the signal Φ _E becomes high, and the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m becomes active.

That is, if the output level of the 1-bit memory circuit 235 is low, this embodiment operates similarly to the fourth embodiment. Therefore, the differential amplifier circuit forming the ultra short circuit of the input circuits 220 _{3 to} 220 _m starts from the time when the chip select signal / CS goes high after a predetermined delay time after the chip select signal / CS goes low. It becomes active only for a period until a predetermined delay time has elapsed. Input circuitry (220 ₃ ~220 _m) becomes inactive during another time. As a result, since the input circuits 220 _{3 to} 220 _m are not always active, power consumption of the input circuit portion can be effectively reduced.

On the other hand, when the output level of the 1-bit memory circuit 235 is high, the output of the OR circuit 236, that is, the activation signal Φ _E is fixed at the high level, forming an ultra short circuit of the input circuits 220 _{3 to} 220 _m . The differential amplifier circuit is constantly active. Therefore, in this case, this embodiment operates similarly to the SDRAM shown in FIG.

Therefore, according to this embodiment, when the output level of the 1-bit memory circuit is low, the power consumption of the input circuit portion can be reduced similarly to the fourth embodiment.

The 1-bit memory circuit 235 has a known configuration for storing a high level or low level signal depending on whether a predetermined fuse is blown, the presence of a predetermined wiring, and the presence of a junction to a predetermined pad or the like. Can be. In such a case, the storage contents of the 1-bit memory circuit 235 can be set at the manufacturing stage of the semiconductor device.

A sixth embodiment of the semiconductor device according to the present invention will be described below with reference to FIG. Fig. 27 shows the construction of a part of the sixth embodiment. In this embodiment, a differential amplifier circuit activation circuit 238 is provided instead of the differential amplifier circuit activation circuit 233 of the fifth embodiment. The differential amplifier circuit activation circuit 238 has a configuration different from that of the differential amplifier circuit activation circuit 233 of the fifth embodiment. Otherwise, the sixth embodiment is essentially the same as the fifth embodiment described above.

The configuration of the differential amplifier circuit activation circuit 238 is similar to the differential amplifier circuit activation circuit 233 except that a one-bit memory circuit 239 is provided instead of the one-bit memory circuit 235.

1-bit storage circuit 239 and the write is output from the latch circuit (203 ₂₎ the row address strobe signal / RAS, a latch circuit (203, ₃₎ the column address strobe signal / CAS, and a latch circuit (203, ₄₎ outputted from the output from the Receive the enable signal / WE.

28 shows the configuration of the 1-bit memory circuit 239. As shown in FIG. The one-bit memory circuit 239 shown in FIG. 28 includes inverters 240 to 242, NAND circuits 243, AND circuits 244, VCC power lines 245, and increased pMOS transistors connected as shown. 246, incremental nMOS transistor 247, latch circuit 248, and inverter 251.

An inverter (240 241) inverts the row address strobe signal / RAS is output from the latch circuit (203 _2). Inverter 242 inverts the write enable signal / WE is output from the latch circuit (203 _4). NAND circuit 243 is output as a latch circuit (203 _3), a column address strobe signal / CAS output from the latch circuit NAND operation with the write enable signal / WE is output from the (203 ₄₎ of the inverter (240) Obtain AND circuit 244 calculates an AND operation between the column address strobe signal / CAS output from the output of the inverter (241 242) and a latch circuit (203 _3).

The VCC power supply line 245 supplies the power supply voltage VCC. The on / off state of the pMOS transistor 246 is controlled by the output of the NAND circuit 243, and the on / off state of the nMOS transistor 247 is controlled by the output of the AND circuit 244. Latch circuit 248 includes inverters 249 and 250. The output terminal of the inverter 251 is connected to the OR circuit 236 shown in FIG.

In the 1-bit memory circuit 239, as shown in FIG. 29, if the level of the row address strobe signal / RAS is low, the level of the column address strobe signal / CAS becomes high, and the level of the write enable signal / WE. Becomes high. That is, when an active command is input, the output level of the NAND circuit 243 goes low, the pMOS transistor 264 turns on, the output level of the AND circuit 244 goes low, and the nMOS transistor 247 Is off. As a result, the output level of the inverter 249 is set low, the output level of the inverter 250 is set high in the latch circuit 248, and the output level of the inverter 251 becomes high.

Therefore, in this case, the output level of the OR circuit 236, that is, the level of the activation signal Φ _E becomes high, and the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m remains in an active state. do. Therefore, the embodiment in this case operates similarly to the SDRAM shown in FIG.

On the other hand, in the 1-bit memory circuit 239, if the level of the row address strobe signal / RAS is low, the level of the column address strobe signal / CAS becomes high, and the level of the write enable signal / WE is shown in FIG. Goes low as shown. That is, when a precharge command is input, the output level of the NAND circuit 243 becomes high, the pMOS transistor 246 is turned off, the output level of the AND circuit 244 becomes high, and the nMOS transistor 247 Is turned on. As a result, in the latch circuit 248, the output level of the inverter 249 is set high, the output level of the inverter 250 is set low, and the output level of the inverter 251 goes low.

Thus, in this case, the output level of the OR circuit 236, that is, the output of the inverter 234 shown in Fig. 27, is activated by the activation signal Φ _E in the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m . Supplied as.

Therefore, if the level of the chip select signal / CS supplied from the outside is high in this case, the level of the chip select signal / CS output from the input circuit 202 ₂ is high, and the level of the activation signal Φ _E is low. The differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m becomes inactive.

However, if the chip enable level of the signal / CS is supplied from outside the low in this case, the level of the chip select signal / CS is outputted from the input circuit (202 ₂₎ is low, the level of the activation signal Φ _E is high The differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m becomes active.

The row address strobe signal / RAS is low, the column address strobe signal / CAS is high, the write enable signal / WE is high, and the row address strobe signal / RAS is low, and the column address strobe signal is low. Except when the level of the / CAS is high and the level of the write enable signal / WE is low, the output level of the NAND circuit 243 becomes high, the pMOS transistor 246 is turned off, and the AND circuit 244 Output level is low, nMOS transistor 247 is turned off, and latch circuit 248 remains in its previous state.

In this embodiment, the automatic refresh cycle is set eight times after the power is turned on. When the auto refresh cycle ends, the operation is automatically changed to precharge operation.

Therefore, after the power is turned on, the latch circuit 248 maintains the high level output of the inverter 249 and the low level output of the inverter 250. Therefore, the output level of the inverter 251 is low, the output of the inverter 234 is output as the enable signal Φ _E. The activation signal Φ _E is supplied to the input circuit (220 ₃ ~220 _m) makes a differential amplifier circuit of the input circuit (220 ₃ ~220 _m) active.

And then, make the differential amplifier circuit when the activation command is input, the chip select signal / CS to form a first stage circuit are of the transition to the low level input circuits (220 ₃ ~220 _m) active. Therefore, bits A _{n to} A ₁ of the address signal and control signals / RAS, / CAS, / WE, and DMQ other than the chip select signal / CS are input.

When an activation command is input, in the latch circuit 248 as shown in Fig. 29, the output level of the inverter 249 is set low and the output level of the inverter 250 is set high. Therefore, the output level of the inverter 251 goes high. As a result, the level of the activation signal Φ _E becomes high, and the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m is constantly active, and this embodiment shows the SDRAM shown in FIG. It works similarly to

Then, when the precharge command is input, in the latch circuit 248 shown in Fig. 30, the output level of the inverter 249 is set high and the output level of the inverter 250 is set low. Therefore, the output level of the inverter 251 goes low. As a result, the output of the inverter 234 is supplied as an activation signal Φ _E to the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m , and this embodiment operates similarly to the fourth embodiment. . This state is then maintained until an active command is entered.

When the chip select signal / CS transitions from the high level to the low level when the activation command is input, the activation signal Φ _E transitions from the low level to the high level after a predetermined time delay. For this reason, when inputting an active command, the input timing of the chip select signal / CS must be determined in consideration of this predetermined time delay.

Fig. 31 is a timing chart for explaining the input timing of the chip select signal / CS when an activation command is input. Fig. 31 shows timings of clock signals CLK, chip select signal / CS, control signals / RAS, / CAS, / WE, and DQM other than chip select signal / CS, and bits A _{n to} A ₁ of the address signal. It is shown.

That is, in this embodiment, when the setup time t _SETUP required for the control signal and the address signal is 2 ns, for example, the setup time t _SETUP-CS of the chip select signal / CS at the time of active command input is input circuit (220 _3). The differential amplifier circuit forming the ultra-short circuit of ˜220 m) should be set longer than the setup time t _SETUP in consideration of the time taken from the high level to the low level of the chip select signal / CS to become active.

However, after the active command is inputted, the differential amplifier circuit forming the ultra short circuit of the input circuits 220 _{3 to} 220 _m remains in the active state until the precharge command is input, similar to the SDRAM shown in FIG. Will be. In this case, therefore, it is sufficient to make the setup time t _SETUP-CS of the chip select signal / CS equal to the setup time t _SETUP .

In Fig. 31, the holding time t _HOLD required for the control signal and the address signal is set to 2 ns, for example. This holding time t _HOLD is sufficient as the holding time of the chip select signal / CS.

Therefore, according to the present embodiment, the differential amplifier circuit forming the ultra short circuit of the input circuits 220 _{3 to} 220 _m starts from the time when the chip select signal / CS transitions to the low level when an active command is input. It becomes active only for a period up to the time when the precharge command is input. The differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m is inactive for another time. As a result, since the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m is not constantly active, power consumption of the input circuit portion can be effectively reduced.

Next, a seventh embodiment of a semiconductor device according to the present invention will be described with reference to FIG. This embodiment uses the one-bit memory circuit 239 shown in FIG. 32 instead of the one-bit memory circuit 239 of the sixth embodiment shown in FIG. Otherwise, this embodiment is essentially the same as the sixth embodiment. 32, the same reference numerals are given to the same portions as the corresponding portions of FIG. 28, and description thereof will be omitted.

An nMOS transistor 253 is provided in the one-bit memory circuit 239 shown in FIG. Otherwise, the one bit memory circuit 239 shown in FIG. 32 is essentially the same as the one bit memory circuit 239 shown in FIG.

The drain of the nMOS transistor 253 is connected to an input terminal of the latch circuit 248, that is, an input terminal of the inverter 249. The source of nMOS transistor 253 is grounded. In addition, an automatic precharge change signal Φ _P is supplied to the gate of the nMOS transistor 253.

Automatically changing the precharge signal Φ _P has a for a predetermined period of time to automatically change the precharge operation at a high level, the others are kept at a low level. This automatic precharge change signal? _P is generated inside the semiconductor device. For example, an automatic change to a precharge operation occurs when a write operation is executed, which operation then moves to a precharge operation in accordance with a write with automatic precharge command instructing an automatic precharge operation. Is changed.

nMOS transistor 253 is turned off and is turned on when the automatic precharge level of change signal Φ _P is high when in the auto precharge level of change signal Φ _P low.

In this embodiment, the automatic refresh cycle is set eight times after the power is turned on. However, the operation is automatically changed to precharge operation at the end of the automatic refresh cycle.

Therefore, after the power is turned on, the latch circuit 248 maintains the high output level of the inverter 249 and the low output level of the inverter 250, and the output level of the inverter 251 goes low. The output of the inverter 234 is output as an enable signal Φ _E, makes the differential amplifier circuit forming the first stage circuit of the input circuit (220 ~220 _{3 m)} thus inactive.

Then, when an active command is input, the pMOS transistor 246 is turned on and the nMOS transistor 247 is turned off. Therefore, the output level of the inverter 249 of the latch circuit 248 goes low, the output level of the inverter 250 goes high, and the output level of the inverter 251 goes high. As a result, the level of the activation signal Φ _E becomes high, and the differential amplifier circuits forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m are constantly in an active state. Thus, in this case, this embodiment operates similarly to the SDRAM shown in FIG.

Then, when the precharge command is input, the pMOS transistor 246 is turned off and the nMOS transistor 247 is turned on. Therefore, the output level of the inverter 249 goes high, the output level of the inverter 250 goes low, and the output level of the inverter 251 goes low. As a result, the output of the inverter 234 is supplied as an activation signal Φ _E to the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m , so that this embodiment operates similarly to the fourth embodiment. Is set. This state is then maintained until an activation command is entered.

Further, after the level of the activation signal Φ _E becomes high and the differential amplifier circuits forming the ultra short circuit of the input circuits 220 _{3 to} 220 _m become active, the level of the automatic precharge change signal Φ _P becomes high. The nMOS transistor 253 is turned on when the operation is changed to precharge operation according to the automatic precharge write command. As a result, the output level of the inverter 249 of the latch circuit 248 goes high, the output level of the inverter 250 goes low, and the output level of the inverter 251 goes low.

Accordingly, the output of the inverter 234 is also supplied as an activation signal Φ _E to the differential amplifier circuit forming the ultrashort circuit of the input circuits 220 _{3 to} 220 _m even in this case. Therefore, in this case, this embodiment is set to operate similarly to the fourth embodiment, and this state is then maintained until an active command is input.

If the chip select signal / CS is transitioned from the high level to the low level when the activation command is input, the activation signal Φ _E is transitioned from the low level to the high level after a predetermined delay time. Therefore, similar to the sixth embodiment, it is necessary to determine the input timing of the chip select signal / CS in consideration of this predetermined delay time when the activation command is input.

Therefore, according to the present embodiment, the differential amplifier circuit constituting the ultrashort circuit of the input circuits 220 _{3 to} 220 _m is precharged from the time when the chip select signal / CS transitions to the low level when an active command is input. It remains active for a period up to the time the command is input or for a period from the time when the chip select signal / CS transitions to the low level until the time when the operation is changed to the precharge operation according to the automatic precharge write command. The differential amplifier circuit constituting the ultrashort circuit of the input circuits 220 _{3 to} 220 _m is inactive for the rest of the time, and therefore is not continuously active. This can reduce power consumption of the input circuit portion.

33 shows another configuration of the input circuit 202 ₁ shown in FIG. In FIG. 33, the same reference numerals are given to the same parts as those in FIG. 22, and the description thereof will be omitted.

The input circuit 202 ₁ shown in FIG. 33 includes a differential amplifier circuit 204, a VCC power supply line 205 for supplying a power supply voltage VCC of 3.3V, and inverters 211 to 213, for example. The differential amplification circuit 204 includes incremental pMOS transistors 206 and 207, incremental nMOS transistors 208 and 209, incremental nMOS transistor 210, and incremental pMOS transistors 281 and 282. Incremental pMOS transistors 206 and 207 are p-channel metal insulating semiconductor (MIS) transistors that form a current mirror circuit and form a load. Incremental nMOS transistors 208 and 209 are n-channel MIS transistors and form drive transistors. Increase-type nMOS transistor 210 is acting as a resistor element, and control on / off by the enable signal Φ _E. On / off of the pMOS transistor enhancement (281 282) state is also controlled by the enable signal Φ _E. Inverters 211 to 213 are provided for shaping waveforms, and the output of the inverter 213 is connected to the clock signal input terminals of the input circuits 203 _{1 to} 203 _m-1 shown in FIG.

In the differential amplifier circuit 204 shown in Fig. 33, the threshold voltage V _IH on the high level side is 1.7V, and the threshold voltage V _IL on the low level side is 1.3V.

When the activation signal Φ _E is at the high level, in the input circuit 202 ₁ shown in Fig. 33, the nMOS transistor 210 is turned on, the pMOS transistors 281 and 282 are turned off, and the differential amplifier circuit 204 is active. It is in a state.

In the input circuit 202 ₁ shown in Fig. 33, when the clock signal CLK is at the high level, the nMOS transistor 208 is turned on, the nMOS transistor 209 is turned off, and the voltage at the node 214 is low. Level. As a result, the output level of the inverter 211 becomes high, the output level of the inverter 212 becomes low, the output level of the inverter 213 becomes high, and the high level output of the inverter 213 is latched. It is supplied to the clock signal input terminal of the circuits 203 _{1 to} 203 _m-1 .

On the other hand, when the clock signal CLK is at a low level, the nMOS transistor 208 is turned off, the nMOS transistor 209 is turned on, and the voltage at the node 214 is at a high level. As a result, the output level of the inverter 211 becomes low, the output level of the inverter 212 becomes high, the output level of the inverter 213 becomes low, and the low level output of the inverter 213 is latched. It is supplied to the clock signal input terminal of the circuits 203 _{1 to} 203 _m-1 .

In addition, when the activation signal Φ _E is at the low level, the nMOS transistor 210 is turned off, the pMOS transistors 281 and 282 are turned on, and the differential amplifier circuit 204 is inactive. Moreover, the output of the differential amplifier circuit 204 is fixed at a high level.

A so-called burn-in test is performed to remove a semiconductor device having a latent defect before transferring the semiconductor device such as the SDRAM shown in FIG. 21 to the next step. The burn-in test is to test the operation of the semiconductor device for a predetermined time under high temperature conditions.

On a so-called burn-in board for burn-in test, for example, 100 to 200 semiconductor devices are mounted. For this reason, the length of the wiring on the burn-in board becomes long, and the rise and fall of the clock signal CLK becomes considerably slow. If the noise is mixed with the rising waveform and falling waveform of the clock signal CLK, the latch circuits (203 ₁ ~203 _m-1) will become a normal burn-in test is erroneous operation is executed can be performed.

Next, an eighth embodiment of the semiconductor device according to the present invention in which a normal burn-in test can be performed even when noise is mixed in the clock signal CLK during the burn-in test will be described.

First, the operation principle of the eighth embodiment will be described with reference to FIG. The semiconductor device shown in FIG. 34 includes a clock signal input terminal 320, an information signal input terminal 321, an input circuit 322, an input circuit 323, and a latch circuit 324 connected as shown. do.

The clock signal CLK is supplied to the clock signal input terminal 320 from the outside, and the information signal is supplied to the information signal input terminal 321 from the outside.

The input circuit 322 amplifies the clock signal CLK received through the clock signal input terminal 320. The input circuit 323 amplifies the information signal received through the information signal input terminal 321. The latch circuit 324 latches the information signal output from the input circuit 323 at a timing determined by the rising or falling edge of the clock signal CLK output from the input circuit 322. The latch circuit 324 has a clock signal input terminal 324A for receiving the clock signal CLK and an information signal input terminal 324B for receiving the information signal.

Input circuit 322 includes threshold logic circuits 325 and 326 and selection circuit 327. The threshold logic circuit 326 has a high level threshold V _IH that is higher than the threshold of the threshold logic circuit 325. The threshold logic circuit 326 also has a low level threshold V _IL that is lower than the threshold of the threshold logic circuit 325. Threshold logic circuit 326 is inactive during normal operation and becomes active during burn-in tests. The selection circuit 327 selectively outputs the clock signal CLK output from the threshold logic circuit 325 to the clock signal input terminal 324A of the latch circuit 324 during normal operation. On the other hand, the selection circuit 327 selectively outputs the clock signal CLK output from the threshold logic circuit 326 to the clock signal input terminal 324A of the latch circuit 324 during the burn-in test.

The high level threshold V _IH of the threshold logic circuit 326 is higher than the threshold value of the threshold logic circuit 325, and the low level threshold V _IL of the threshold logic circuit 326 is higher than the threshold value of the threshold logic circuit 325. Since it is lower than the threshold, the threshold logic circuit 326 is more noise resistant than the threshold logic circuit 325. When performing the burn-in test, the clock signal CLK output from the threshold logic circuit 326 is supplied to the clock signal input terminal 324A of the latch circuit 324.

Therefore, even when noise is mixed with the rising waveform or the falling waveform of the clock signal CLK when the burn-in test is performed, a normal burn-in test can be executed by preventing a malfunction.

Next, an eighth embodiment will be described in more detail with reference to FIGS. 35 to 40. In the present embodiment, the present invention is applied to the SDRAM.

35 shows a part of the eighth embodiment. 35, the same reference numerals are given to the same portions as the corresponding portions of FIG. 21, and the description thereof will be omitted.

In this embodiment, there is provided instead of the input circuit (202 ₁ ~202 _m) and an input circuit having a different circuit configuration (330 ₁ ~330 _m) an input circuit (202 ₁ ~202 _m) shown in Fig. In addition, a test control signal Φ _T is supplied to each input circuit 330 _{1 to} 330 _m . In addition, the configuration of this embodiment shown in FIG. 35 is essentially the same as the SDRAM shown in FIG.

The input circuits 330 _{1 to} 330 _m may all have the same circuit configuration. For example, the input circuit 330 ₁ has the configuration shown in FIG. The input circuit 330 ₁ shown in FIG. 36 includes a differential amplifier circuit 331, an inverter 340, a NOR circuit 341, and a selection circuit 347 connected to each other as shown.

The differential amplifier circuit 331 includes, for example, a VCC power supply line 332 for supplying a power supply voltage VCC of 3.3 V, increased pMOS transistors 333 and 334 for forming a current mirror circuit and forming a load, and an increase for forming a driving transistor. type nMOS includes a transistor (335 336), and activation signal Φ _E on / off control enhancement nMOS transistor 337, and enhancement-pMOS transistors (338 339) is oN / oFF controlled by the enable signal Φ _E is by. The differential amplifier circuit 331 has a high level threshold V _{IH of} 1.7V and a low level threshold V _IL of 1.3V with respect to the clock signal CLK.

The inverter 340 inverts the tester control signal Φ _T , and the output of the inverter 340 is supplied to the NOR circuit 341 and the selection circuit 347.

The NOR circuit 341 includes a VCC power supply line 342 for supplying a power supply voltage VCC, incremental pMOS transistors 343 and 344, and incremental nMOS transistors 345 and 346. The NOR circuit 341 has a high level threshold V _IH of 2.2 V and a low level threshold V _IL of 0.8 V with respect to the clock signal CLK.

The selection circuit 347 includes NAND circuits 348 and 349 and inverters 350 and 351. The output of the inverter 351 is connected to the clock signal input terminal of the latch circuits 203 _{1 to} 203 _m-1 shown in FIG.

During normal operation of this embodiment, the test control signal Φ _T is fixed to the low level, the output of the inverter 340 is fixed to the high level as shown in Fig. As a result, in the NOR circuit 341, the pMOS transistor 343 is turned off and the nMOS transistor 346 is turned on. Thus, the NOR circuit 341 is inactive and the output of the NOR circuit 341 is fixed at a low level.

In addition, in the selection circuit 347, since the output of the inverter 340 is fixed at a high level, the NAND circuit 348 operates as an inverter with respect to the output of the differential amplifier circuit 331. On the other hand, since the output of the NOR circuit 341 is fixed at a low level, the output of the inverter 350 is fixed at a high level, and the NAND circuit 349 operates as an inverter with respect to the output of the NAND circuit 348.

For example, if the activation signal Φ _E has a high level, the differential amplifier circuit (331), nMOS transistor 337 is turned on, pMOS transistors (338 339) is turned off. Thus, the differential amplifier circuit 331 becomes active.

In this case, when the clock signal CLK has a high level, the nMOS transistor 335 is turned on, the nMOS transistor 336 is turned off, and the voltage at the node 352 becomes low level. As a result, the output level of the NAND circuit 348 becomes high in the selection circuit 347, the output level of the NAND circuit 349 becomes low, and the output level of the inverter 351 becomes high. The high level output of the inverter 351 is supplied to the clock signal input terminal of the latch circuits 203 _{1 to} 203 _m-1 .

On the other hand, when the clock signal CLK is at the low level, in the differential amplifier circuit 331, the nMOS transistor 335 is turned off, the nMOS transistor 336 is turned on, and the voltage level at the node 352 is shown in FIG. It goes high as shown. As a result, in the selection circuit 347, the output level of the NAND circuit 348 goes low, the output level of the NAND circuit 349 goes high, and the output level of the inverter 351 goes low. The low level output of the inverter 351 is supplied to the latch circuits _{(203 1 ~203 m-1)} .

Although not an example, when the activation signal Φ _E may be of a low level, nMOS transistor 337 is turned on and off, pMOS transistors (338 339) is turned on. Thus, the differential amplifier circuit 331 is inactive and the voltage level at the node 352 is high.

On the other hand, during the burn-in test example of the present embodiment, the test control signal Φ _T has a high level, the output level of the inverter 340 is low, as shown in Figure 39. As a result, in the NOR circuit 341, the pMOS transistor 343 is turned on and the nMOS transistor 346 is turned off. Therefore, for the clock signal CLK, the NOR circuit 341 operates as a CMOS inverter composed of the pMOS transistor 344 and the nMOS transistor 345.

In the selection circuit 347, the output of the NAND circuit 348 is fixed at a high level, and the NAND circuit 349 operates as an inverter with respect to the output of the NOR circuit 341.

For example, when the clock signal CLK has a high level, in the NOR circuit 341, the pMOS transistor 344 is turned off, the nMOS transistor 345 is turned on, and the output level of the NOR circuit 341 is turned low. . As a result, in the selection circuit 347, the output level of the inverter 350 goes high, the output level of the NAND circuit 349 goes low, and the output level of the inverter 351 goes high. The high level output of the inverter 351 is supplied to the clock signal input terminals of the latch circuits 203 _{1 to} 203 _m-1 .

On the other hand, when the clock signal CLK is at the low level, in the NOR circuit 341 as shown in Fig. 40, the pMOS transistor 344 is turned on and the nMOS transistor 345 is turned off. In this case, the output level of the NOR circuit 341 goes high. As a result, the output level of the inverter 350 becomes low in the selection circuit 347, the output level of the NAND circuit 349 becomes high, and the output level of the inverter 351 becomes low. The low level output of the inverter 351 is supplied to clock signal input terminals of the latch circuits _{(203 1 ~203 m-1)} .

Thus, according to this embodiment, the differential amplifier circuit 331 having the high level threshold V _IH of 1.7 V and the low level threshold V _IL of 1.3 V is used as the input circuit for the clock signal CLK during normal operation.

On the other hand, during the burn-in test, the NOR circuit 341 having a high level threshold V _IH of 2.2 V and a low level threshold V _IL of 0.8 V is stronger in noise than the differential amplifying circuit 331, and is more resistant to the clock signal CLK. It is used as an input circuit.

Therefore, even when noise is mixed in the rising or falling waveform of the clock signal CLK during the burn-in test, the present embodiment can prevent the malfunction and execute the burn-in test in the normal manner.

Furthermore, in this embodiment, the input circuits 330 _{2 to} 330 _m provided for the information signal such as the chip select signal / CS have the same circuit configuration as the input circuit 330 ₁ provided for the clock signal CLK. For this reason, even when noise is mixed in the information signal, a malfunction can be prevented and the burn-in test can be executed in a normal manner.

FIG. 41 shows a part of the SDRAM, and FIG. 42 is a timing diagram for explaining the read operation of the SDRAM.

The SDRAM shown in FIG. 41 includes a clock input circuit (or clock input buffer) 402 and a data output circuit (or data output buffer) 404. The system clock signal CLK is supplied to the clock input terminal 401 from the outside, and the system clock signal CLK is input to the clock input circuit 402. The clock input circuit 402 forms the internal clock signal INT _CLK with the system clock signal CLK. The data output circuit 404 is configured to output the data DQ through the data input / output terminal 403 in synchronization with the rising timing of the internal clock signal INT _CLK supplied from the clock input circuit 402 based on the data already latched. do.

42 shows the system clock signal CLK supplied to the clock input terminal 401, the internal clock signal INT _CLK output from the clock input circuit 402, and the data DQ output from the data output circuit 404. FIG.

For example, when a read command is inputted to the SDRAM shown in Fig. 41 at the timing of rising of the nth clock (pulse) of the system clock signal CLK, the read command actually forms the nth clock (pulse) of the system clock signal CLK. It is input at the rising timing of the nth clock (pulse) of the internal clock signal INT _{CLK to be} obtained.

Then, when the n + 2th clock (pulse) of the system clock signal CLK rises, the data output circuit 404 synchronizes the data DQ in synchronization with the rising timing of the n + _2th clock (pulse) of the internal clock signal INT _CLK . The operation to output to the outside is started, and the data DQ is output to the outside after a predetermined time delay.

Therefore, according to the SDRAM shown in Fig. 41, the data DQ is output after _a delay time t _a from the timing of rising of the closest clock (pulse) of the system clock signal CLK. The delay time t _a is the sum of the delay time of the clock input circuit 402 and the delay time of the data output circuit 404. This delay time t _a is also referred to as access time t _a from the system clock signal CLK. This access time t _a is an output confirmation time at which previous data is continuously output.

The clock input circuit 402 and the data output circuit 404 are composed of MOS transistors. For this reason, when the power supply voltage changes or the temperature is generated, the threshold value and current driving capability of the MOS transistor change. In this case, the access time t _a from the system clock signal CLK changes. In other words, the output confirmation time will change, and the correct data will not be entered at the destination of the data transmission.

Next, the semiconductor according to the present invention which can suppress the change in the access time from the system clock signal caused by the change in the supply voltage and the change in the temperature supplied from the outside so that accurate data can be input to the destination of the data transfer. A ninth embodiment of the apparatus will be described.

First, the operation principle of the ninth embodiment will be described with reference to FIG. The semiconductor device shown in Fig. 43 includes a constant voltage generating circuit 408, a clock input circuit 409 and a data output circuit 410. The system clock signal CLK is supplied to the clock signal input terminal 406 from the outside. Data DQ is input and output via data input / output terminal 407.

The constant voltage generation circuit 408 generates a constant voltage VII having a voltage value for suppressing the change in the operating speed of the transistor with respect to the temperature change. The clock input circuit 409 receives the constant voltage VII from the constant voltage generating circuit 408 as the power supply voltage, and the system clock signal CLK is input from the clock signal input terminal 406. The clock input circuit 409 forms the internal clock signal INT _CLK with the system clock signal CLK. The data output circuit 410 outputs the data DQ to the outside via the data input / output terminal 407 in synchronization with the rise timing or fall timing of the internal clock signal INT _CLK .

In this embodiment, the clock input circuit 409 receives a constant voltage VII having a voltage value that suppresses the change in the operating speed of the transistor with respect to the temperature change as the power supply voltage. Therefore, it is possible to suppress the change in the delay time of the clock input circuit 409 caused by the change in the power supply voltage supplied from the outside and the change in temperature.

Next, a ninth embodiment will be described in detail with reference to FIGS. 44 to 53. In this embodiment, the present invention is applied to SDRAM.

Figure 44 shows an important part of the ninth embodiment. 44 shows the connected terminals 412 to 418, 419 _{1 to} 419 _n , 420, the DRAM core 421, the constant voltage generating circuit 422, the clock input circuit 423, the command decoder 424, and the like. An address input circuit 425, a data input circuit 426, and a data output circuit 427.

The external power supply voltage VCC is supplied to the power supply voltage input terminal 412, the system clock signal CLK is supplied to the clock signal input terminal 413, and the reference voltage Vref is supplied to the reference voltage input terminal 414.

The chip select signal / CS is supplied to the chip select signal input terminal 415, the row address strobe signal / RAS is supplied to the column address strobe signal input terminal 416, and the column address strobe signal / CAS is the column address strobe signal input. Is supplied to the terminal 417, and the write enable signal / WE is supplied to the write enable signal input terminal 418.

The bits A _{1 to} A _n of the address signals are supplied to the address signal input terminals 419 _{1 to} 419 _n , respectively. Data input / output terminal 420 is used to input and output data.

The DRAM core 421 is provided with a memory cell array, sense amplifier, row decoder, column decoder, column gate, and the like. The constant voltage generator circuit 422 generates the constant voltage VII.

The clock input circuit 423 receives the system clock signal CLK supplied from the outside, and forms the internal clock signal INT _CLK with the system clock signal CLK. The clock input circuit 423 outputs this internal clock signal INT _CLK to the command decoder 424, the address input circuit 425, the data input circuit 426, and the data output circuit 427.

The command decoder 424 decodes a command consisting of a chip select signal / CS, a row address strobe signal / RAS, a column address strobe signal / CAS, and a write enable signal / WE. In the address input circuit 425, bits A _{1 to} A _n of the address signal are input. The data input circuit 426 receives data supplied from the outside during the write operation. The data output circuit 427 outputs data during the read operation.

45 shows the structure of the constant voltage generator circuit 422. The constant voltage generator circuit 422 shown in FIG. 45 includes a VCC power supply line 429, a depletion nMOS transistor 430, an increased nMOS transistor 431, and a resistor for supplying a power supply voltage connected as shown. 432. The nMOS transistor 430 has a drain connected to the VCC power line 429 and a gate grounded. The nMOS transistor 431 has a gate and a drain connected to each other, and the drain of the nMOS transistor 431 is connected to the source of the nMOS transistor 430. One end of the resistor 432 is connected to the source of the nMOS transistor 431, and the other end of the resistor 432 is grounded. The constant voltage VII is obtained from the node 433 connecting the resistor 432 and the source of the nMOS transistor 431.

The threshold voltage V _THD (H, T) of the nMOS transistor 430 at high temperature is represented by Equation 1 below. Here, V _THD (R, T) represents the threshold voltage of the nMOS transistor 430 at normal temperature or room temperature, and ΔV _THD represents the deviation of the threshold voltage V _THD due to temperature change.

V _THD (H, T) = V _THD (R, T) -V _THD

In addition, the threshold voltage V _THE (H, T) of the nMOS transistor 431 at high temperature is represented by the following equation (2). Here, V _THE (R, T) represents the threshold voltage of the nMOS transistor 431 at normal temperature or room temperature, and ΔV _THE represents the deviation of the threshold voltage V _THE due to temperature change.

V _THE (H, T) = V _THE (R, T) -V _THE

Since the gate of the nMOS transistor 430 is grounded, the constant voltage VII becomes | V _THD | -V _THE . Therefore, the constant voltage VII (R, T) at normal (or standard) temperature is represented by the following equation (3), and the constant voltage VII (H, T) at high temperature is represented by equation (4).

Further, the threshold voltage V _THD (L, T) of the nMOS transistor 430 at low temperature is represented by the following equation (5), and the threshold voltage V _THE (L, T) of the nMOS transistor 431 at low temperature is Is expressed by Equation 6, and the constant voltage VII (L, T) at low temperature is expressed by the following Equation 7.

V _THD (L, T) = V _THD (R, T) + V _THD

V _THE (L, T) = V _THE (R, T) + V _THE

Therefore, the relationship between the external power supply voltage VCC, the temperature and the constant voltage VII in the constant voltage generating circuit 422 is as shown in FIG. That is, within the predetermined range, the constant voltage VII becomes larger than the constant voltage at the normal temperature when the temperature is high, and becomes smaller than the constant voltage at the normal temperature when the temperature is low.

Thus, in this embodiment, the constant voltage generator circuit 422 is configured to generate a constant voltage VII having a voltage value for suppressing the change in the operating speed of the transistor with respect to the temperature change.

47 shows the configuration of the clock input circuit 423. The clock input signal 423 shown in Fig. 47 includes a VII power supply line 435 for supplying a constant voltage VII, a differential amplifier circuit 436, and inverters 442 to 444 for X-shaping.

The differential amplification circuit 436 includes an incremental pMOS transistors 437 and 438 forming a current mirror circuit and constituting a load, an incremental nMOS transistors 439 and 440 forming a driving transistor, and an incremental nMOS transistor 441 functioning as a resistance element. It includes. The system clock signal CLK is supplied to the gate of the nMOS transistor 439, and the reference voltage Vref is supplied to the gate of the nMOS transistor 440. nMOS transistor 441 is turned on / off by the enable signal Φ _E.

The inverter 442 is composed of an incremental pMOS transistor 445 and an incremental nMOS transistor 448. The inverter 443 is composed of an incremental pMOS transistor 446 and an incremental nMOS transistor 449. The inverter 444 is composed of an incremental pMOS transistor 447 and an incremental nMOS transistor 450.

When the activation signal Φ _E has a low level, in the clock input circuit 423 shown in Fig. 47, the nMOS transistor 441 is turned off, the differential amplifier circuit 436 is inactive, and the clock input circuit ( 423 does not function.

On the other hand, when the enable signal Φ _E is at the high level, nMOS transistor 441 is turned on, the differential amplifier circuit 436 is active.

In this case, when the system clock signal CLK is at a low level as shown in Fig. 48, the nMOS transistor 439 is turned off, the nMOS transistor 440 is turned on, and the level at the node 451 is high. The output level of the inverter 422 becomes low, the output level of the inverter 443 becomes high, and the level of the internal clock signal INT _CLK becomes low.

On the other hand, when the system clock signal CLK goes high as shown in Fig. 49, the nMOS transistor 439 is turned on, the nMOS transistor 440 is turned off, and the level at the node 451 is turned low. Then, the output level of the inverter 442 becomes high, the output level of the inverter 443 becomes low, and the level of the internal clock signal INT _CLK becomes high.

50 shows the configuration of the data output circuit 427. In Fig. 50, RD represents read data read from the DRAM core 421, and / RD represents inverted read data in which read data RD is inverted.

The data output circuit 427 includes the transfer gate circuits 453 to 456, the inverters 465 and 466, the latch circuits 467 to 470, the inverter 479, and the level shift circuits connected as shown in FIG. 480 and output transistors 487 and 488.

The transfer gate circuit 453 is composed of an incremental pMOS transistor 457 and an incremental nMOS transistor 461. The transfer gate circuit 454 is composed of an incremental pMOS transistor 458 and an incremental nMOS transistor 462. The transfer gate circuit 455 is composed of an incremental pMOS transistor 459 and an incremental nMOS transistor 463. The transfer gate circuit 456 is composed of an incremental pMOS transistor 460 and an incremental nMOS transistor 464.

Inverters 465 and 466 invert the internal clock signal INT _CLK output from the clock input circuit 423, respectively.

The latch circuit 467 is composed of inverters 471, 472, the latch circuit 468 is composed of inverters 473, 474, the latch circuit 469 is composed of inverters 475, 476, and the latch circuit 470 is an inverter ( 477,478).

Inverter 479 inverts the output of latch circuit 469. The level shift circuit 480 includes an incremental pMOS transistor 485 and an incremental nMOS transistor 486 connected as shown. The output transistor 487 is composed of an incremental pMOS transistor forming a pull-up element, and the output transistor 488 is composed of an incremental nMOS transistor forming a pull-down element.

Constant voltage VII is provided to inverters 465, 466, 471 to 479 as power supply voltages. On the other hand, the external power supply voltage VCC is provided to the output transistor circuit (or drive circuit) composed of the level sheet circuit 480 and the output transistors 487 and 488 as the power supply voltage.

In the data output circuit 427, when the internal clock signal INT _CLK is at the low level as shown in Fig. 51, the transfer gate circuit 457 is turned on, and the transfer gate circuit 458 is turned off, and the transfer is performed. Gate circuit 459 is turned on and transfer gate circuit 460 is turned off.

In this case, when the level of the read data RD is high and the level of the inverted read data / RD is low, the output level of the latch circuit 467 is low, and the output level of the latch circuit 468 is high. do.

Then, when the internal clock signal INT _CLK transitions to the high level, the transfer gate circuit 457 is turned off, the transfer gate circuit 458 is turned on, and the transfer gate circuit 459 is turned off, and the transfer gate is turned off. Circuit 460 is turned on. As a result, the output level of the latch circuit 469 goes high, the output level of the inverter 479 goes low, and the nMOS transistor 488 is turned off.

In addition, pMOS transistor 482 is turned off, nMOS transistor 485 is turned on, the level at node 489 is low, the output level of latch circuit 470 is low, and the pMOS transistor 484 is turned on and nMOS transistor 486 is turned off. As a result, the pMOS transistor 483 is turned on, the level at the node 490 is high, the pMOS transistor 481 is turned off, the pMOS transistor 487 is turned on, and is in phase with the read data RD. A high level with is output as data DQ.

On the other hand, when the internal clock signal INT _CLK is at the low level, as shown in Fig. 52, the read data RD has a low level, and the inverted read data / RD has a high level. The output level of the latch circuit 467 goes high, and the output level of the latch circuit 468 goes low.

Then, when the internal clock signal INT _CLK transitions to the high level, the transfer gate circuit 457 is turned off, the transfer gate circuit 458 is turned on, and the transfer gate circuit 459 is turned off, and the transfer gate is turned off. Circuit 460 is turned on. As a result, the output level of the latch circuit 469 goes low, the output level of the inverter 479 goes high, and the nMOS transistor 488 is turned on.

In addition, the pMOS transistor 482 is turned on, the nMOS transistor 485 is turned off, the output level of the latch circuit 470 is turned high, the pMOS transistor 484 is turned off, and the nMOS transistor 486 is turned off. Is turned on and the level at node 490 goes low. As a result, the pMOS transistor 481 is turned on, the level at the node 489 is high, the pMOS transistor 483 is turned off, and the pMOS transistor 487 is turned off, which is the same as the read data RD. The low level with phase is output as data DQ.

Moreover, when the internal clock signal INT _CLK is at the low level, as shown in Fig. 53, the read data RD has a high level and the inverted read data / RD has a high level. The output level of the latch circuit 467 goes low, and the output level of the latch circuit 468 goes low.

Then, when the internal clock signal INT _CLK transitions to the high level, the transfer gate circuit 457 is turned off, the transfer gate circuit 458 is turned on, and the transfer gate circuit 459 is turned off, and the transfer gate is turned off. Circuit 460 is turned on. As a result, the output level of the latch circuit 469 goes high, the output level of the inverter 479 goes low, and the nMOS transistor 488 is turned off.

In addition, the pMOS transistor 482 is turned on, the nMOS transistor 485 is turned off, the output level of the latch circuit 470 is turned high, the pMOS transistor 484 is turned off, and the nMOS transistor 486 is turned off. Is turned on and the level at node 490 goes low. As a result, the pMOS transistor 481 is turned on, the level at the node 489 is high, the pMOS transistor 483 is turned off, the pMOS transistor 487 is turned off, and the output state is high impedance. It becomes (Hi-Z) state.

In this embodiment, when inputting a read command at the rising timing of the nth clock (pulse) of the system clock signal CLK similarly to the case described above with reference to Fig. 42, the read command is actually the nth clock of the system clock signal CLK. It is input at the rising timing of the nth clock (pulse) of the internal clock signal INK _CLK obtained by shaping (pulse).

Therefore, the data output circuit 427, for example, synchronizes the DRAM with the rising timing of the n + 1 th clock (pulse) of the internal clock signal INT _CLK obtained by shaping the n + 1 th clock (pulse) of the system clock signal CLK. The latch circuits 467 and 468 latch the read data RD and the inverted read data / RD outputted from the core 421.

As an example, when the n + 2th clock (pulse) of the system clock signal CLK rises, the data output circuit 427 performs an internal clock signal INT _CLK obtained by shaping the n + 2nd clock (pulse) of the system clock signal _CLK . The operation of outputting the data DQ having the same phase as the read data RD to the outside in synchronization with the rising timing of the n + 2th clock (pulse) is started. Therefore, the data DQ is output to the outside with a predetermined time delay.

Therefore, in this embodiment, the data DQ is output with a delay corresponding to the access time t _a from the system clock signal CLK. However, in this embodiment, the clock input circuit 423 is supplied with a constant voltage VII having a voltage value for suppressing the change in the operating speed of the transistor with respect to the temperature change. For this reason, it is possible to suppress the change in the delay time of the clock input circuit 423 caused by the change in the externally supplied power supply voltage VCC and the temperature change.

In addition, in this embodiment, the constant voltage VII is provided as a power supply voltage to a circuit portion of the data output circuit 427 other than the output transistor circuit composed of the level shift circuit 480 and the output transistors 487 and 488. Therefore, it is possible to suppress the change in the delay time of the data output circuit 427 due to the change in the externally supplied power supply voltage VCC and the temperature change.

Therefore, according to this embodiment, since the change in the access time from the system clock signal CLK due to the change in the externally supplied power supply voltage VCC and the temperature change can be suppressed, accurate data can be input to the destination of the data transfer. .

Next, another SDRAM and its problems will be described with reference to FIGS. 54 and 55. FIG.

Fig. 54 shows a clock input circuit of the SDRAM. This SDRAM includes a differential amplifier circuit 510, pMIS transistors 520 and 521, an inverter 530, a NAND circuit 531, and an inverter 532 connected as shown. The differential amplifier circuit 510 includes nMIS transistors 511, 512, 513 and a current mirror circuit 517. Current mirror circuit 517 includes pMIS transistors 514 and 515 and nMIS transistor 516.

In Figure 54, the externally supplied clock signal CK2 has an extremely high frequency in the range of 50 MHz to 200 MHz. Therefore, clock signal CK2 has a terminated low voltage transistor-transistor logic (T-LVTTL) level. That is, the clock signal CK2 is terminated by a 50Ω resistor. Since the logic amplitude of the clock signal CK2 is extremely small, the lower limit of the high level is 1.5 + 0.4V and the upper limit of the low level is 1.5-0.4V. In order to prevent malfunction, the characteristics of the circuit elements are determined such that a high level is detected for a 1.5 + 0.2V input and a low level is detected for a 1.5-0.2V input.

On the other hand, in the SDRAM, a voltage of about 3.3 V is used between the power supply line Vii and the ground line Vss. In addition, a signal having a high level of about 3V and a low level of about 0V is used. Therefore, clock signal CK2 is amplified in differential amplifier circuit 510.

When the enable signal EN1 has a low level, the nMIS transistor 513 is turned off and the pMIS transistors 520 and 521 are turned on. Therefore, the differential amplifier circuit 510 is in an inactive state, and the drain potential of the nMIS transistors 511 and 512 becomes the potential of the power supply line Vii.

When the enable signal EN1 transitions to the high level, the nMIS transistor 513 is turned on, the pMIS transistors 520 and 521 are turned off, and the differential amplifier circuit 510 is in an active state. During this transition, the differential amplifier circuit 510 is immediately activated because the drain potential of the nMIS transistors 511 and 512 has already reached the potential Vii.

In this state, when the clock signal CK2 is provided to the gate of the nMIS transistor 511, the clock signal CK3 is output from the differential amplifier circuit 510. The clock signal CK3 is a signal in which the clock signal CK2 is inverted and amplified.

The clock signal CK3 is provided to the inverter 530. The NAND circuit 531 obtains the NAND operation of the output of the inverter 530 and the enable signal EN2, and the inverter 532 inverts the output of the NAND circuit 531 to the clock signal CK4.

FIG. 55 is a diagram showing a simulation result for the SDRAM shown in FIG. 54. FIG. From Fig. 55, when the clock signal CK2 transitions from 1.5-0.3V to 1.5 + 0.3V with respect to the reference voltage Vref of 1.5V, from clock signal CK2 becomes 1.5V until clock signal CK3 becomes 1.5V. It can be seen that the required signal propagation delay time is 0.42 ns.

Because of the input capacitance of the inverter 530, the signal propagation delay time of 0.42 ns is relatively long compared to 0.2 ns, which is the transition time of the clock signal CK2.

The tenth to twelfth embodiments of the semiconductor device according to the present invention, which can reduce the signal propagation delay time by adding a simple circuit to the differential amplifier circuit, will be described with reference to Figs.

Fig. 56 shows the configuration of the SDRAM applied to the tenth to twelfth embodiments of the present invention. The SDRAM 501 shown in FIG. 56 includes a clock input circuit 502, a buffer circuit 503, and other circuits 504 connected as shown.

The clock input circuit 502 receives the clock signal CK1 and the enable signal EN1 from the outside. The buffer circuit 503 receives the enable signal EN1. This buffer circuit 503 amplifies the enable signal EN1 to generate the enable signal EN2. The circuit 504 operates in synchronization with the clock signal CK4 output from the clock input circuit 502.

The clock input circuit 502 is activated when the level of the enable signal EN1 becomes high, and amplifies the clock signal CK1 to generate the clock signal CK4. When the level of the enable signal EN1 goes high, the clock input circuit 502 provides the clock signal CK4 to the circuit 504.

As mentioned above, the clock signal CK1 has an extremely high frequency in the range of 50 MHz to 200 MHz, and has the T-LVTTL level described above with an extremely small logic amplitude. In addition, to prevent malfunction due to noise, the clock input circuit 502 has a margin of 0.2V for the high and low levels of the input signal. Therefore, transistor characteristics are determined such that a high level is detected for an input signal of 1.5 + 0.2V and a low level is detected for an input signal of 1.5-0.2V.

On the other hand, the clock input circuit 502, the buffer circuit 503, and the circuit 504 operate with a voltage of 3.3 V, for example, a voltage between the power supply line Vii and the ground line Vss. In circuit 504, the signal used has a high level of about 3V and a low level of about 0V.

Fig. 57 shows the construction of a part of the tenth embodiment. In particular, FIG. 57 shows the configuration of the clock input circuit 502. In Fig. 57, the same reference numerals are given to the same parts as the corresponding parts in Fig. 54, and the description thereof will be omitted.

In this embodiment, an input terminal circuit 540 is provided in front of the circuit shown in FIG. In addition, since the input stage circuit 540 performs inversion and amplification, an inverter 533 is provided between the differential amplifier circuit 510 and the inverter 530.

The input terminal circuit 540 includes nMIS transistors 541 and 543 and pMIS transistors 544 and 550 connected as shown in FIG.

In the differential amplifier circuit 510, the sources of the nMIS transistors 511 and 512 are connected to the ground line Vss via the nMIS transistor 513. The drains of the nMIS transistors 511 and 512 are connected to the power supply line Vii via the pMIS transistors 514 and 515, respectively. The nMIS transistors 511 and 512 have the same characteristics, and the pMIS transistors 514 and 515 have the same characteristics. The gate of the pMIS transistor 514 is connected to the drain of the pMIS transistor 515. The nMIS transistor 516 is connected between the gate and the drain of the pMIS transistor 515. The gate of the nMIS transistor 516 is connected to the power supply line Vii and functions as a load FET. The pMIS transistors 520 and 521 are connected in parallel to the pMIS transistors 514 and 515, respectively.

On the other hand, in the input terminal circuit 540, the source of the nMIS transistor 541 is connected to the ground line Vss via the nMIS transistor 543. The drain of the nMIS transistor 541 is connected to the power supply line Vii via the pMIS transistor 544. The pMIS transistor 550 is connected in parallel to the pMIS transistor 544, and the gate of the pMIS transistor 544 is connected to the gate of the pMIS transistor 514. The nMIS transistors 541 and 543 and the pMIS transistors 544 and 550 correspond to the nMIS transistors 511 and 513 and the pMIS transistors 514 and 520, respectively. For example, corresponding components have the same characteristics.

The pMIS transistors 514 and 515, the nMIS transistor 516 and the pMIS transistor 544 form a current mirror circuit 518. The currents I14, I15 and I44 flowing through the pMIS transistors 514, 515 and 544, respectively, are controlled by the drain potential of the pMIS transistor 515 so as to be equal to each other.

The gates of the nMIS transistors 513,543 and the pMIS transistors 520,521,550 are commonly connected, and an enable signal EN1 is provided.

The gate and the drain of the nMIS transistor 541 form an input and an output of the input terminal circuit 540, respectively, and a clock signal CK1 is provided to the input of the input terminal circuit 540. The gate and the drain of the nMIS transistor 411 form the input and the output of the differential amplifier circuit 510, respectively. The input of the differential amplifier circuit 510 is connected to the output of the input stage circuit 540, and the clock signal CK2 from the input stage circuit 540 is provided to the input of the differential amplifier circuit 510. The reference potential Vref having a predetermined voltage is applied to the gate of the nMIS transistor 512 forming a pair with the nMIS transistor 511.

The output of the differential amplifier circuit 510 is connected to one input of the NAND circuit 531 via inverters 533 and 530. Enable signal EN2 is provided to the other input of NAND circuit 531. The output of the NAND circuit 531 is connected to the input of the inverter 532, and the clock CK4 is output from the inverter 532.

Next, the operation of the present embodiment will be described.

When the enable signal EN1 is at the low level, the nMIS transistors 513,543 are turned off, the pMIS transistors 520,521,550 are turned on, and the differential amplifier circuit 510 and the input stage circuit 540 are in an inactive state. In addition, the drain potentials of the nMIS transistors 511, 512, 541 become Vii.

When the enable signal EN1 transitions to the high level, the nMIS transistors 513,543 are turned on, the pMIS transistors 520,521,550 are turned off, and the differential amplifier circuit 510 and the input stage circuit 540 are in an active state. During this transition, the differential amplifier circuit 510 and the input stage circuit 540 are immediately activated because the drain potential of the nMIS transistors 511, 512, 541 is already Vii.

Next, a description will be given of the case where the enable signal EN1 has a high level.

The potential of the high level enable signal EN1 is constant, and the nMIS transistors 513 and 543 serve as constant current sources. The currents I13 and I14 flowing through the nMIS transistors 513 and 543, respectively, are I43 = I13 / 2 = constant values. In the steady state, ΔI1 = ΔI2 = 0, where ΔI1 represents the current derived from the gate of the nMIS transistor 511, and ΔI2 represents the current injected into the gate of the CMOS forming the inverter 533. Indicates.

58 shows simulation results obtained in the present embodiment shown in FIG. First, assume that to in FIG. That is, the level of the clock signal CK1 is low, the level of the clock signal CK2 is high, and the level of the clock signal CK3 is low.

(1) When clock signal CK1 transitions from low level to high level:

In this case, when the clock signal CK1 transitions to the high level, the drain potential of the nMIS transistor 541, that is, the potential of the clock signal CK2 becomes lower than the reference potential Vref, thereby satisfying? I10. Therefore, I14I15 is satisfied, the drain potential of the nMIS transistor 511, that is, the potential of the clock signal CK3 rises (ΔI20), and the drain potential of the nMIS transistor 512 drops. Since I44 = I14, I44 decreases due to I14I15, while ΔI1 increases because I43 is constant. By this positive feedback, the potential drop of the clock signal CK2 and the potential rise of the clock signal CK3 are accelerated. When the potential of the clock signal CK2 is too low, the gate potential of the pMIS transistor 544 drops due to the drop in the drain potential of the nMIS transistor 512, and DELTA I10 is satisfied by increasing I44.

Accordingly, clock signals CK2 and CK3 change as shown in FIG. 58 with respect to clock signal CK1. For ease of comparison of Figs. 58 and 55, the circuit characteristics of the components of Fig. 57 are the same as those of Fig. 54, and the circuit characteristics of the inverter 533 are the same as those of the inverter 530. Is configured. In this case, Vii is 3.3V, Vss is OV, and Vref is 1.5V.

In FIG. 58, the time required for the clock signal CK3 to start rising at the low level after the clock signal CK1 starts rising at the low level is slightly longer than in FIG. However, in Fig. 58, the signal propagation delay time from the time when the clock signal CK1 becomes 1.5V to the time when the clock signal CK3 becomes 1.5V is 0.3 ns, which is 58% of the propagation delay time 0.52 ns in Fig. 55. It is only. Incidentally, the inclination of the clock signal CK3 in FIG. 58 is steeper than that in FIG.

Therefore, according to the tenth embodiment, the signal propagation delay time can be reduced to 58% of the signal propagation delay time required in the circuit shown in Fig. 54 by adding only four FETs to the circuit shown in Fig. 54.

(2) When clock signal CK1 transitions from high level to low level:

When the clock signal CK1 transitions to the low level, ΔI10 is satisfied by raising the drain potential of the nMIS transistor 541, that is, the potential of the clock signal CK2. Therefore, I14I15 is satisfied, the drain potential of the nMIS transistor 511, that is, the potential of the clock signal CK3 drops (ΔI20), and the drain potential of the nMIS transistor 512 rises. Since I44 = I14, I44 rises by I14I15, and -ΔI1 increases because I43 is constant. By this positive feedback, the potential rise of the clock signal CK2 and the potential drop of the clock signal CK3 are accelerated. If the potential of the clock CK2 becomes too high, the gate potential of the pMIS transistor 544 rises and I44 decreases, thereby ΔI10 is satisfied.

Therefore, when the clock signal CK1 transitions from the high level to the low level, the signal propagation delay is reduced similarly to the case (1) described above.

Of course, the inverters 533 and 530 may be omitted.

59 shows the construction of a part of the eleventh embodiment. In FIG. 59, the same reference numerals are given to the same parts as the corresponding parts in FIG. 57, and description thereof will be omitted.

In this embodiment, the gate of pMIS transistor 544 is grounded without being connected to the gate of pMIS transistor 514. The pMIS transistor 544 functions as a load FET. In this case, it can be confirmed through simulation results that the signal propagation delay time is reduced by the amplifying function of the input terminal circuit 540 compared with the circuit shown in FIG.

FIG. 60 shows simulation results for this embodiment shown in FIG. In comparison with Fig. 58, it can be seen from Fig. 60 that the instability of the clock signal CK2 is removed immediately after the drop in the eleventh embodiment.

In addition, since the gate of the pMIS transistor 544 is grounded, the resistance of the pMIS transistor 544 becomes smaller than in the tenth embodiment. Therefore, the size of the pMIS transistor 544 can be reduced.

As a modification of the eleventh embodiment, the gate of the pMIS transistor 544 can be connected to the drain of the pMIS transistor 544. The effect achieved by this modification is essentially the same as the effect obtainable in the eleventh embodiment.

Fig. 61 shows a part of the twelfth embodiment. In Fig. 61, the same reference numerals are given to the same parts as those in Fig. 57, and a description thereof will be omitted.

In this embodiment, the nMIS transistor and the pMIS transistor in the differential amplifier circuit 410 and the input terminal circuit 540 shown in FIG. 57 are replaced with each other as shown in FIG. In addition, the power supply line Vii and ground line Vss shown in FIG. 57 are replaced with each other as shown in FIG. The operation of this embodiment is essentially the same as that of the tenth embodiment shown in Fig. 57, and the description thereof is omitted.

In a modification of the twelfth embodiment, instead of connecting the gate of the nMIS transistor 544 to the gate of the nMIS transistor 514, the gate of the nMIS transistor 544 is connected to the drain of the nMIS transistor 544 or the power supply line Vii. Can be. In this case, the nMIS transistor 544 functions as a load FET. When the gate of the nMIS transistor 544 is connected to the power supply line Vii, the resistance of the nMIS transistor 544 is reduced, and the size of the nMIS transistor 544 can be reduced.

In the tenth to twelfth embodiments, the nMIS or pMIS transistor 516 of the current mirror circuit 510 may be omitted, and instead, this portion may be a short circuit. It is also possible to use a current mirror circuit having another known circuit configuration. Moreover, the transistors can be any type of FET, including MES transistors.

According to the synchronous semiconductor memory device of the present invention, the clock input circuit is supplied with a constant voltage having a voltage value for suppressing the change in the operation speed of the transistor according to the temperature change. Therefore, it is possible to prevent the change in the delay time of the clock input circuit due to the change in the externally supplied power supply voltage and the temperature change. In addition, a constant voltage can be supplied as a power supply voltage to a circuit portion of an output transistor circuit composed of a data output circuit and an output transistor other than the level shift circuit. Therefore, it is possible to prevent the change in the delay time of the data output circuit due to the change in the power supply voltage and the temperature change supplied from the outside. In addition, since the change in the access time from the system clock signal due to the change in the supply voltage and the temperature supplied from the outside can be prevented, accurate data can be input to the destination of the data transfer.

The present invention is not limited to the above-described embodiments, and many modifications and variations can be made without departing from the spirit of the present invention.

Claims (13)

A clock input circuit for receiving a system clock signal and shaping the system clock signal to output an internal clock signal; A data output circuit connected to said clock input circuit and performing a data output operation in synchronization with the rising or falling timing of said internal clock signal output from said clock input circuit; A constant voltage generating circuit connected to said clock input circuit, generating a constant voltage having a voltage value for suppressing a change in the operating speed of a transistor with respect to a temperature change, and supplying said constant voltage as said power supply voltage to said clock input circuit; A synchronous semiconductor memory device, characterized in that. 2. The data output circuit according to claim 1, wherein the data output circuit includes an output circuit having an output transistor and a level converting circuit, wherein the constant voltage generating circuit uses the constant voltage as a power supply voltage for the data output circuit other than the level converting circuit and the output circuit. A synchronous semiconductor memory device characterized by being supplied to a circuit. The method of claim 1, wherein the constant voltage generation circuit, A first depletion n-channel insulated gate type field effect transistor having a drain and a grounded gate connected to a power supply line for supplying a power supply voltage; A second incremental n-channel insulated gate field effect transistor having a gate and a drain connected to each other and the drain connected to a source of the first field effect transistor; A resistor having one end connected to a source of the second field effect transistor and the other end grounded; And a node which connects one end of said resistor and a source of said second field effect transistor to form an output end of said constant voltage generating circuit for outputting said constant voltage. A current mirror circuit having three pairs of current input stages and current output stages; A first constant current source having a current input end and a current output end, a first end connected to one of the current input end and the current output end of the first constant current source, and a second end connected to the first end and the second end of the current mirror circuit, respectively First and second field effect transistors having stages, wherein the first and second stages of the current mirror circuit are two input terminals or two output terminals of the current mirror circuit, and the second field effect transistor has a reference potential. A differential amplifier circuit having a gate supplied thereto; A third constant current source having a current input end and a current output end, a third end having a first end connected to one of the current input end and the current output end of the second constant current source and a second end connected to the third end of the current mirror circuit; A field effect transistor, wherein the third end of the current mirror circuit has an input end circuit which is an input end or an output end of the current mirror circuit other than the first end and the second end of the current mirror circuit, And an output signal corresponding to the amplified signal of the input signal supplied to the gate of the third field effect transistor is output from a second stage of one of the first and second field effect transistors. 5. The current mirror circuit of claim 4, wherein the one of the current input terminal and the current output terminal of the first constant current source is a current input terminal, and the one of the current input terminal and the current output terminal of the second constant current source is a current input terminal. The first to third stages of the semiconductor integrated circuit, characterized in that the current output terminal. The method of claim 5, wherein the current mirror circuit, A fourth field effect transistor having a current input terminal connected to a first power line and a current output terminal forming a first stage of the current mirror circuit; A current input terminal connected to the first power supply line, a current output terminal forming a second stage of the current mirror circuit, a second terminal of the current mirror circuit, and a gate connected to a gate of the fourth field effect transistor A fifth field effect transistor; And a sixth field effect transistor having a current input terminal connected to the first power line, a current output terminal forming a third stage of the current mirror circuit, and a gate connected to the gate of the fourth field effect transistor. A semiconductor integrated circuit characterized by. 7. The circuit of claim 6, wherein the current mirror circuit further comprises a seventh field effect transistor connected between a gate and a current output terminal of the fifth field effect transistor, wherein the seventh field effect transistor is connected to the first power line. A semiconductor integrated circuit having a gate connected thereto. 6. The apparatus of claim 5, wherein the first constant current source comprises an eighth field effect transistor having a current output terminal connected to a second power supply line having a lower potential than the first power supply line and a gate to which an enable signal is supplied; And the second constant current source comprises a ninth field effect transistor having a current output terminal connected to the second power supply line and a gate to which the enable signal is supplied. The current mirror circuit of claim 4, wherein the one of the current input terminal and the current output terminal of the first constant current source is a current output terminal, and the one of the current input terminal and the current output terminal of the second constant current source is a current output terminal. The first to third stages of the semiconductor integrated circuit, characterized in that the current input terminal. 5. The apparatus according to claim 4, further comprising first to third switching elements respectively connected between corresponding pairs of current input and current output stages of the three pairs of current input and current output stages of the current mirror circuit, And said first to third switching elements are turned on / off during an active / inactive state of an enable signal. A synchronous semiconductor memory device comprising a clock input circuit and wherein the semiconductor integrated circuit according to claim 4 is provided to the input clock circuit. And the clock input circuit receives a clock signal having a voltage amplitude smaller than that of the signal processed in the clock input circuit. A current mirror circuit having two pairs of current input and output ends; A first constant current source having a current input end and a current output end, a first end connected to one of the current input end and the current output end of the first constant current source, and a second end connected to the first end and the second end of the current mirror circuit, respectively First and second field effect transistors having stages, wherein the first and second stages of the current mirror circuit are two input terminals or two output terminals of the current mirror circuit and are referenced to a gate of the second field effect transistor. A differential amplifier circuit to which a potential is supplied; A second constant current source having a current input stage and a current output stage, a load field effect transistor, a first stage connected to one of the current input stage and the current output stage of the second constant current source, a gate of the first field effect transistor, and the load field A third field effect transistor having a second end connected to one end of the effect transistor, the other end of the load field effect transistor having an input terminal circuit connected to a power supply line, And an output signal corresponding to the amplified signal of the input signal supplied to the gate of the third field effect transistor is output from a second stage of one of the first and second field effect transistors. A synchronous semiconductor memory device comprising a clock input circuit and wherein the semiconductor integrated circuit according to claim 12 is provided to the clock input circuit. And the clock input circuit receives a clock signal having a voltage amplitude smaller than that of the signal processed in the clock input circuit.