JPH05325568A - Input circuit device - Google Patents

Abstract

PURPOSE:To match the signal levels of different voltages with each other between semiconductor integrated circuits (chip) such as LSIs which differ in operating voltage when the chips are both present. CONSTITUTION:A signal with the voltage level (signal level) of a source voltage VDD1 is inputted to an input protecting circuit 10. At this time, an n-channel transistor(TR) 13 is always ON. The signal inputted to the input protecting circuit 10 is lowered in voltage by a threshold voltage through the n-channel TR 3 and inputted to the driver circuit 11 of the following stage. Then a driver circuit 11 converts the signal into a signal having the voltage level of a source voltage VDD2. Therefore, a voltage converting circuit need not be used to match the signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MIS semiconductor integrated circuit device (metel insulator semiconductor).
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input circuit of a semiconductor integrated circuit such as an n.

[0002]

2. Description of the Related Art In recent semiconductor integrated circuits such as MIS semiconductor integrated circuits, the miniaturization of LSIs has been developed along with the demand for higher integrated circuits, and the development of low voltage LSIs has also been advanced. In such a current situation, for example, two power supply system chip circuits, that is, a 5V operation system chip circuit and a 3V operation system chip circuit may coexist in an LSI system, and a signal between chip circuits having different power supply voltages may be transmitted. In order to match the signal level (voltage level) between the two, a voltage conversion circuit capable of converting the voltage level is provided with an SSI (small s)
call integration) or MSI (me
It has been necessary to provide it on a semiconductor integrated circuit by a double scale circuit. FIG. 5 specifically shows this state. In FIG. 5, 50 and 54 are 5V operation circuits, 50 and 53 are voltage conversion circuits composed of SSI and MSI, and 52 is a 3V (3.3V) operation circuit (LS).
I). Next, FIG. 6 is a circuit diagram showing an input circuit generally used in a conventional MIS semiconductor integrated circuit device. In FIG. 6, 10 is an input protection circuit composed of diodes D1 and D2 and a resistor R1, 11 is a driver circuit composed of two stages of inverters, and VDD1 is a power supply voltage.

Next, the operation of this conventional example will be described. When a signal of "H" voltage level is input to the input terminal (in) of the input protection circuit I0, this signal is output to the output terminal (out) via the driver circuit 11. At this time, in the driver circuit 11, since the upper inverter (comprising a P-channel transistor) forming this circuit is turned on, a signal at the voltage level of the power supply voltage VDD1 is output. Similarly, when a signal of "L" voltage level is input to the input terminal (in) of the input protection circuit 10, the output terminal (out) of the driver circuit 11 is at the ground level "L". "Signal is output. Therefore, in order to output a signal from this driver circuit to a circuit having a power supply voltage different from the power supply voltage VDD1, the voltage conversion circuits 51 and 54 as shown in FIG. 5 are required.

[0004]

Since the input circuit of the conventional MIS semiconductor integrated circuit is configured as described above, when exchanging signals between circuits having different power supply voltages or in a system having different power supply voltages. When using the LSI circuit in, in order to match the voltage level signal,
It is necessary to provide the voltage conversion circuits 51 and 54 shown in FIG. 5 between the external circuit and the LSI circuit. Therefore, there is a problem that the integration degree in the system of the semiconductor integrated circuit is lowered and the manufacturing cost is increased.

The present invention has been made in order to solve the above problems, and an input capable of voltage conversion of a signal between circuits having different power supply voltages without providing a special circuit such as a voltage conversion circuit. An object is to provide a circuit device.

[0006]

In the input circuit device according to the first aspect of the present invention, as shown in FIG.
1 and a grounded two diodes D1 and D2 connected in series, and a first resistor R1 having one end connected between the two diodes, and an input signal is applied between the two diodes. In an input circuit device including an input protection circuit 10 that receives an input signal and outputs an output signal from the other end of the first resistor, and a driver circuit 11 that drives a driven circuit by voltage, Has a second power supply VDD2 that supplies a low voltage to the driver circuit, and a control terminal connected to the first power supply, and outputs the output signal of the input protection circuit when it is turned on by a voltage drop amount. Switching semiconductor element (n-channel) for converting the output signal into a signal having the same voltage level as that of the second power source by inputting the output signal into the driver circuit. With a transistor 13) and.

In the input circuit device according to the second invention,
As shown in FIG. 1, in an input circuit device including the input protection circuit and the driver circuit, a second voltage that is lower than the voltage of the first power source is supplied to the driver circuit.
Power supply VDD2 and a control terminal connected to this second power supply, and when it is turned on, the output signal of the input protection circuit is dropped by a voltage drop, and the dropped output signal is A switching semiconductor element (n-channel transistor 13) for converting the output signal into a signal having the same voltage level as the second power source by inputting the output signal to the driver circuit is provided.

In the input circuit device according to the third invention,
As shown in FIG. 3, two diodes D1 and D2 connected in series between the first power supply VDD1 and ground.
And a first resistor R having one end connected between both diodes
And an input protection circuit 10 in which an input signal is input between the diodes and an output signal is sent from the other end of the first resistor, and a first driver circuit for driving the driven circuit by voltage. And a second power supply VDD2 for supplying a voltage lower than the voltage of the first power supply to the first driver circuit, and an output signal of the input protection circuit for the first power supply. A second driver circuit 12 which converts the signal to a signal having a voltage level of 1 and outputs the signal, and a control terminal connected to the first power source, and outputs the second driver circuit when turned on. Switching for dropping the signal by a voltage drop and outputting the dropped output signal to the first driver circuit to convert the output signal into a signal having the same voltage level as the second power supply. And a conductive element (n-channel transistor 13).

In the input circuit device according to the fourth invention,
As shown in FIG. 3, in an input circuit device including the input protection circuit and the driver circuit, a second power supply that supplies a voltage lower than the voltage of the first power supply to the first driver circuit, It has a second driver circuit 12 for converting the output signal of the input protection circuit into a signal having the voltage level of the first power supply and sending it out, and a control terminal connected to the second power supply, and is in an ON state. Then, the output signal of the second driver circuit is dropped by a voltage drop, and the dropped output signal is output to the first driver circuit to output the output signal to the second power supply. And a switching semiconductor element (n-channel transistor 13) for converting a voltage to a signal having the same voltage level as the above.

In the input circuit device according to the fifth invention,
As shown in FIG. 4, two diodes D1 and D2 connected in series between the first power supply VDD1 and ground.
And a first resistor R having one end connected between both diodes
1, an input signal is input between the diodes, and an output signal is sent from the other end of the first resistor, and an input protection circuit 10 and a driver circuit 11 for driving the driven circuit by voltage. An input circuit device comprising: a second power supply VD for supplying the voltage of the first power supply to the driven circuit.
D2 and a control terminal connected to the first power source,
When turned on, the output signal of the driver circuit is dropped by a voltage drop, and the dropped output signal is output to the driven circuit, so that the output signal becomes the voltage of the second power supply. A switching semiconductor element (n-channel transistor 13) for converting a voltage to a signal having the same voltage level is provided.

In the input circuit device according to the sixth invention,
As shown in FIG. 4, in the input circuit device including the input protection circuit and the driver circuit, the second power supply VDD2 that supplies the voltage of the first power supply to the driven circuit.
And a control terminal connected to the second power source, and when it is turned on, the output signal of the driver circuit is dropped by a voltage drop, and the dropped output signal is sent to the driven circuit. A switching semiconductor element (n-channel transistor 13) for converting the output signal into a signal having the same voltage level as the voltage of the second power source by outputting the voltage is provided.

[0012]

In the input circuit device according to the first aspect of the present invention, the signal having the voltage level of the power supply voltage VDD1 is input through the resistor R1 of the input protection circuit 10, and the switching semiconductor element (n-channel transistor 13) causes a voltage drop. (Threshold voltage), the driver circuit 11
Entered in. Then, the signal is output from the driver circuit 11 as a signal having the voltage level of the power supply voltage VDD2. As a result, the signal of the voltage level of the power supply voltage VDD1 can be converted into the signal of the voltage level of the power supply voltage VDD2 by at least one of the switching semiconductor elements, which eliminates the need for the conventional voltage conversion circuit. The switching semiconductor element is always on.

In the input circuit device according to the second invention,
The control terminal of the switching semiconductor element was connected to the second power source instead of the first power source to perform the same operation as that of the first invention.

In the input circuit device according to the third invention,
A signal having a small voltage level is input to the second driver circuit via the resistor R1 of the input protection circuit 10 and converted into a signal having a voltage level of the power supply voltage VDD1. The voltage level signal of the power supply voltage VDD1 is dropped by the switching semiconductor element (n-channel transistor 13) by a voltage drop (threshold voltage) and input to the first driver circuit. Then, it is output as a signal having the voltage level of the power supply voltage VDD2. As a result, the voltage level signal of the power supply voltage VDD1 is converted into a voltage level signal of the power supply voltage VDD2. The switching semiconductor element is always on.

In the input circuit device according to the fourth aspect of the present invention,
The control terminal of the switching semiconductor element was connected to the second power source instead of the first power source to perform the same operation as that of the third invention.

In the input circuit device according to the fifth aspect of the present invention,
A signal having the voltage level of the power supply voltage VDD1 is input from the driver circuit 11 to the switching semiconductor element (n-channel transistor 13) and dropped by this switching semiconductor element by a voltage drop (threshold voltage).
It is input to the driven circuit. As a result, the power supply voltage VDD1
The signal having the voltage level of is converted into a signal having the voltage level of the power supply voltage VDD2. Of course, the switching semiconductor element is always on.

In the input circuit device according to the sixth aspect of the present invention,
The control terminal of the switching semiconductor element was connected to the second power source instead of the first power source to perform the same operation as that of the fifth invention.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment (embodiment 1) of the first invention.
3 is a circuit diagram of the input circuit device showing FIG. In FIG. 1, 1
Reference numeral 0 is an input protection circuit including a resistor R1 and two diodes D1 and D2, 11 is a driver circuit, and 13 is an n-channel transistor as a switching semiconductor element. In addition, the same reference numerals are given to portions having the same functions as those of the conventional example (FIG. 6). In the input protection circuit 10, two diodes D1 and D2 are connected in series in the same direction,
The cathode of 1 is connected to the power supply voltage VDD1, and the anode of the diode D2 is connected to the ground (earth). The input side of the n-channel transistor 13 is connected to one end of the resistor R1 of the input protection circuit 10, and the output side thereof is connected to the input side (connection point 1a) of the driver circuit 11.
The gate as a control terminal of the n-channel transistor 13 is connected to the power supply voltage VDD1 and the cathode of the diode D1. The driver circuit 11 is connected between the power supply voltage VDD2 and the ground, and the output side is connected to the output terminal (out).

Since the n-channel transistor 13 is connected to the power supply voltage VDD1, it is normally on. When a signal as shown in FIG. 2 is input to the input side of the n-channel transistor (in in FIG. 2), the voltage is lowered by the threshold voltage VTH (1 in FIG. 2).
a), output from the driver circuit (out in FIG. 2).
As described above, in this embodiment, the "L" potential is transmitted as it is, but the "H" potential is lowered by the threshold voltage of the transistor. Further, the power supply voltage VDD2 is determined by the following equation 1), where the threshold voltage is VTH. VDD2 = VDD1-VTH ... 1) This threshold voltage VTH can be changed by changing the channel doping amount.

Next, the operation of this embodiment will be described. In the voltage protection circuit 10, for example, a signal having a voltage level of the power supply voltage VDD1 = 5V as shown in FIG. 2 is input from the input terminal in and output to the input side of the n-channel transistor 13. Since the gate of the n-channel transistor 13 is connected to the power supply voltage VDD1, the n-channel transistor 13 is always in the ON state, the voltage drops by the threshold voltage VTH = 2V, and the voltage drops in the driver circuit 11 (1a in FIG. 2). Is output. The driver circuit 11 outputs the signal having the voltage level of the lowered power supply voltage VDD2 = 3V to the output terminal out. As a result, a signal having the voltage level of the power supply voltage VDD1 is transferred to the power supply voltage VDD2.
The voltage can be converted into a signal having a voltage level of.

Next, an embodiment (embodiment 2) of the second invention will be described. In the second embodiment, as shown in FIG. 1, the gate of the n-channel transistor 13 and the input protection circuit 10 are connected to the power supply voltage VDD2 (indicated by () in FIG. 1). Note that the other configurations and operations are the same as those in the first embodiment except that the threshold voltage VTH is set to zero, and thus the description thereof is omitted.

Next, an embodiment of the third invention will be described. FIG. 3 is a circuit diagram of an input circuit device showing an embodiment (embodiment 3) of the third invention. In FIG. 3, reference numeral 12 is a driver circuit as a second driver circuit. In the driver circuit 12, the P-channel transistors 12a and n
The channel transistor 12b is connected in series, one end of the p-channel transistor 12a is connected to the power supply voltage VDD1, and one end of the n-channel transistor 12b is connected to the ground. The n-channel transistor 13 is
The input side is connected to the output side of the driver circuit 12, and the output side is connected to the input side of the driver circuit 11. The driver circuit 11 is the same as that of the first embodiment,
The inside of the P-channel transistor 11a is also shown.
And n-channel transistor 11b, and is connected between the power supply voltage VDD2 and the drain. A signal having a small voltage level is input to the driver circuit 12, converted into a signal having the voltage level of the power supply voltage VDD1, and further converted into a signal having the voltage level of the power supply voltage VDD2 in the driver circuit 11. The rest of the configuration and operation are the same as those in the above embodiment, and will not be described.

Next, an embodiment (fourth embodiment) of the fourth invention will be described. In the fourth embodiment, as shown in FIG. 3, the gate of the n-channel transistor 13 and the driver circuit 12 are connected to the power supply voltage VDD2 (indicated by () in FIG. 3). The other configurations and operations are the same as those in the third embodiment except that the threshold voltage VTH is set to zero to eliminate the voltage drop, and therefore the description thereof will be omitted.

Next, an embodiment of the fifth invention will be described. FIG. 4 shows an embodiment (embodiment 5) of the fifth invention.
3 is a circuit diagram of the input circuit device showing FIG. In FIG. 4, 4
Reference numeral 0 denotes an internal circuit as a driven circuit, which is the fifth embodiment.
Then, the n-channel transistor 13 is connected to the driver circuit 11
And an internal circuit such as an LSI. The gate of the n-channel transistor 13 is connected to the power supply voltage VDD1, its input side is connected to the output side of the driver circuit 11, and its output side is connected to the input side of the internal circuit 40. The internal circuit 40 is connected between the power supply voltage VDD2 and the ground. The rest of the configuration and operation are the same as those of the above-mentioned first to fourth embodiments, and therefore their explanations are omitted.

Next, an embodiment (sixth embodiment) of the sixth invention will be described. In the sixth embodiment, as shown in FIG. 4, the gate of the n-channel transistor 13 and the driver circuit 11 are connected to the power supply voltage VDD2 (indicated by () in FIG. 4). Note that the other configurations and operations are the same as those in the fifth embodiment except that the threshold voltage VTH is set to zero to eliminate the voltage drop, and thus the description thereof will be omitted.

[0026]

According to the first and second aspects of the present invention, since the switching semiconductor element is provided between the input protection circuit and the driver circuit, it is possible to perform voltage conversion with a small number of components, and a system such as an LSI is provided. It is possible to improve the degree of integration and reduce the manufacturing cost.

According to the third and fourth inventions, since the switching element is provided between the first driver circuit and the second driver circuit, in addition to the effects of the first and second inventions. There is an effect that even a signal with a small voltage level can be handled.

According to the fifth and sixth aspects of the invention, since the switching element is provided between the driver circuit and the internal circuit, in addition to the effects of the first and second aspects of the invention, such a configuration is provided. There is an effect that can be applied to the input circuit.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an input circuit device showing an embodiment of the first invention.

FIG. 2 is a waveform diagram showing the operation of each part of the apparatus shown in FIG.

FIG. 3 is a circuit diagram of an input circuit device showing an embodiment of the third invention.

FIG. 4 is a circuit diagram of an input circuit device showing an embodiment of the fifth invention.

FIG. 5 is a schematic diagram of a system of a semiconductor integrated circuit device having a voltage conversion circuit according to a conventional technique.

6 is a circuit diagram showing an input circuit in the apparatus of FIG.

[Explanation of symbols]

 10 Input Protection Circuit 11, 12 Driver Circuit 13 n-Channel Transistor 40 Internal Circuit VDD1, VDD2 Power Supply Voltage

[Procedure amendment]

[Submission date] October 5, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a MIS semiconductor integrated circuit device ( metal insulator circuit).
relates an input circuit of a semiconductor integrated circuit nductor circuit) or the like, particularly, it relates to an input circuit device for a voltage converting a signal having a certain voltage level to a signal with other voltage levels.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art In recent semiconductor integrated circuits such as MIS semiconductor integrated circuits, the miniaturization of LSIs has been developed along with the demand for higher integrated circuits, and the development of low voltage LSIs has also been advanced. Under such a current situation, for example, 5V operation system L
In some cases , two power supply type LSIs , SI and 3V operation type LSIs , may coexist in the system, and the voltage level can be converted in order to match the signal voltage level between LSIs having different power supply voltages. The voltage conversion circuit is changed to SSI (sm
all scale integration) or M
SI (medium scale integral)
on ) had to be provided in the system . FIG. 5 specifically shows this state. In FIG. 5, 5
0.54 is 5V operation system circuit, 51, 53 voltage conversion circuit, 52 is 3V (3.3V) operation circuit (LSI). Next, FIG. 6 is a circuit diagram showing an input circuit generally used in a conventional MIS semiconductor integrated circuit device. In FIG. 6, 10 is an input protection circuit composed of diodes D1 and D2 and a resistor R1, 11 is a driver circuit composed of two stages of inverters, and VDD1 is a power supply voltage.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Next, the operation of this conventional example will be described. When a signal of “H” voltage level is input to the input terminal (in) of the input protection circuit 10 , this signal is output to the output terminal (out) via the driver circuit 11. At this time, in the driver circuit 11, the P circuit that constitutes this circuit is
Since the channel transistor is turned on, the power supply voltage VDD1
The signal of the voltage level of is output. In the same way,
When a signal having a voltage level of “L” is input to the input terminal (in) of the input protection circuit 10, a “L” signal that is a ground level is output to the output terminal (out) of the driver circuit 11. .. Therefore, in order to output a signal from this driver circuit to a circuit having a power supply voltage different from the power supply voltage VDD1, the voltage conversion circuits 51 and 54 as shown in FIG. 5 are required.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

Since the input circuit of the conventional MIS semiconductor integrated circuit is configured as described above , signals are exchanged between LSIs having different power supply voltages.
In order to match the voltage level of the signal , the LSI
It is necessary to provide the voltage conversion circuits 51 and 53 shown in FIG. For this reason, the system
There is a problem that the integration degree of the system decreases and the manufacturing cost increases.

Claims (6)

[Claims] 1. A diode comprising two diodes connected in series connected between a first power source and ground, and a first resistor having one end connected between both diodes, wherein the two diodes are connected to each other. An input circuit device comprising an input protection circuit in which an input signal is input to and an output signal is sent out from the other end of the first resistor, and a driver circuit which voltage-drives a driven circuit. It has a second power supply that supplies a voltage lower than the voltage to the driver circuit, and a control terminal connected to the first power supply, and drops the output signal of the input protection circuit when turned on. And a switching semiconductor element for converting the output signal into a signal having the same voltage level as the second power supply by inputting the output signal thus reduced to the driver circuit. Special Input circuit device to be used. 2. A diode, comprising two diodes connected in series connected between a first power source and ground, and a first resistor having one end connected between the two diodes, the diode being connected between the two diodes. An input circuit device comprising an input protection circuit in which an input signal is input to and an output signal is sent out from the other end of the first resistor, and a driver circuit which voltage-drives a driven circuit. It has a second power supply for supplying a voltage lower than the voltage to the driver circuit, and a control terminal connected to this second power supply, and when it is in an ON state, it drops the output signal of the input protection circuit. And a switching semiconductor element for converting the output signal into a signal having the same voltage level as the second power supply by inputting the output signal thus reduced to the driver circuit. Special Input circuit device to be used. 3. A diode including two diodes connected in series connected between a first power source and ground, and a first resistor having one end connected between the two diodes, the diode being connected between the two diodes. The input circuit device comprises an input protection circuit in which an input signal is input to the input circuit and an output signal is sent from the other end of the first resistor, and a first driver circuit which voltage-drives the driven circuit. A second power supply that supplies a voltage lower than the power supply voltage to the first driver circuit, and an output signal of the input protection circuit that is converted into a signal having the voltage level of the first power supply and sent out. The second driver circuit has a control terminal connected to the first power supply, and when turned on, the output signal of the second driver circuit is dropped by a voltage drop, and the dropped output is output. Signal the first above
And a switching semiconductor element for converting the output signal into a signal having the same voltage level as the second power source by outputting the output signal to the driver circuit. 4. A diode including two diodes connected in series connected between a first power source and ground, and a first resistor having one end connected between the two diodes, wherein the two diodes are connected to each other. The input circuit device comprises an input protection circuit in which an input signal is input to the input circuit and an output signal is sent from the other end of the first resistor, and a first driver circuit which voltage-drives the driven circuit. A second power supply that supplies a voltage lower than the power supply voltage to the first driver circuit, and an output signal of the input protection circuit that is converted into a signal having the voltage level of the first power supply and sent out. A second driver circuit and a control terminal connected to the second power source, and when the ON state is reached, the output signal of the second driver circuit is dropped by a voltage drop, and the dropped output Signal the first above
And a switching semiconductor element for converting the output signal into a signal having the same voltage level as the second power source by outputting the output signal to the driver circuit. 5. A diode, comprising: two diodes connected in series connected between a first power source and ground; and a first resistor having one end connected between the two diodes, wherein the two diodes are connected to each other. An input circuit device comprising an input protection circuit in which an input signal is input to and an output signal is sent out from the other end of the first resistor, and a driver circuit which voltage-drives a driven circuit. It has a second power supply for supplying a voltage to the driven circuit and a control terminal connected to the first power supply, and when the ON state is achieved, the output signal of the driver circuit is dropped by a voltage drop. A switching semiconductor element for converting the output signal into a signal having the same voltage level as the voltage of the second power supply by outputting the lowered output signal to the driven circuit. Input to Circuit device. 6. A device comprising: two diodes connected in series connected between a first power source and ground; and a first resistor having one end connected between the two diodes, the diode being connected between the two diodes. An input circuit device comprising an input protection circuit in which an input signal is input to and an output signal is sent out from the other end of the first resistor, and a driver circuit which voltage-drives a driven circuit. It has a second power source for supplying a voltage to the driven circuit and a control terminal connected to the second power source, and when the ON state is reached, the output signal of the driver circuit is lowered by a voltage drop. A switching semiconductor element for converting the output signal into a signal having the same voltage level as the voltage of the second power supply by outputting the lowered output signal to the driven circuit. Input to Circuit device.