JP3397656B2 - Semiconductor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a circuit configuration of a semiconductor device used by boosting a battery voltage in a portable product or the like. It relates to voltage control of a circuit to be started. 2. Description of the Related Art In a portable product using a battery as a power supply, a power supply voltage (V _DD ) of a semiconductor device used for various functions is usually supplied by boosting a battery voltage (V _CC ). . Here, for example, when the portable product is a headphone stereo, examples of functions include playing, fast-forwarding, rewinding, and stopping. Conventionally, a boosted voltage has been used for controlling function keys of a portable product. When the portable product is started, the V _DD boost circuit is first started by the V _CC input circuit, and after the boost is completed, the V _DD input including the control of the function key is performed. For this reason, the input circuit to the _VDD system cannot be used as an input circuit until the battery voltage increases. Therefore, a semiconductor device that controls a power supply voltage and a function needs to separately include a terminal for starting a circuit and a terminal for controlling a function key. Such a conventional technique will be described with reference to FIGS. 4, 5, and 6. FIG. First, the control function of FIG. 4 showing a conventional circuit configuration will be described with reference to FIGS. In FIG.
There is a button 109 for external input consisting of a plurality of control buttons, and a semiconductor set 118 having a comparison circuit and the like is connected to the button 109.
Is connected to an IC 112 including a booster circuit and the like.
FIG. 6 shows an example of the internal configuration of the button 109 in FIG. First, in the conventional method, a start button 119 of the buttons 109 including a start button and various function buttons is pressed in order to start a portable product. Then, a signal 115 from the start button is first sent to the input determination device 110. In the input determination device 110,
Determine whether the start button has been pressed or not pressed.
If the input determination device 110 presses a valid start button (when an invalid button other than the start button is pressed, the input determination device 110 determines that the button is invalid and the portable product does not operate). The booster circuit is activated, and the battery voltage is boosted. Here, the button 109 has a configuration as shown in FIG. 6, and when the start button 119 is pressed, a start signal (corresponding to the signal 115 in FIG. 5) is output to the start terminal 120, and the booster circuit in FIG. It is activated by a Hold signal from a control circuit (not shown). After the boosting is completed, for example, when used for a headphone stereo, various function buttons 12 for playing, fast-forwarding, rewinding, etc.
If any of the 1-124 is pressed, and R ₅ in FIG. 6 R ₆
Function signal voltage determined by the ratio of to R ₇ (corresponding to signal 116 in FIG. 5) is output. After the battery voltage is increased, the selected function signal 116 from the button 109 is sent to the button type determination device 111 in FIG. Button type determination device 111
Then, it is determined which button of the various functions has been pressed. Only when the start button has been pressed, a signal corresponding to the function assigned to the button pressed later is sent to the input terminal 114 of the control circuit 112 as a function command. The above is described with reference to the circuit diagram of FIG. FIG.
As shown in FIG. 5, when a start signal (corresponding to 115 in FIG. 5) is input to the external input terminal 102, V _CC (power supply voltage) 10
4 (which corresponds to a battery or the like in the case of a portable device) is input to a booster circuit 103 using, for example, a DCDC converter or the like, and the battery voltage is boosted. Also, the fact that the start input signal has been input is sent as a signal E to a necessary part of the circuit. Here, the booster circuit 103 is used to raise the voltage of a dry battery or a rechargeable battery (secondary battery) used in a portable device or the like to the operating voltage of various functions of the used device. Required high-voltage driving using a dry battery or a rechargeable battery (secondary battery). The voltage boosted by the boosting circuit 103 is V
_Indicated by _DD . Here, the hold signal 108 to hold the voltage of the V _DD voltage V _DD is input is maintained. The voltage V _DD of the voltage boosted by the boosting circuit 103 is input to the first comparator 105, the second comparator 106, and its peripheral circuits (the button type determination device 1 in FIG. 5).
11). In FIG. 4, two comparators 10
Although only 5 and 106 have been described, if there are four function buttons as shown in FIG. 6, for example, four comparators may be connected. Here, for the first time, signals from the input signal terminal 101 assigned to various buttons are received. When a signal is input from the input signal terminal 101 assigned to each of the various buttons, the signal is compared with a reference voltage via comparators 105 and 106 to determine which button has been pressed. Then, a function command is output as a signal such as C or D. As described above, in the conventional start-up IC for portable equipment, a battery is used as a V _CC power supply, and V _{DD, which} is a boosted battery power supply, is used as a power supply for a CMOS circuit or the like for driving various functions. . Therefore, in order to suppress the consumption of the battery, it is usually good to stop the boosting of V _DD while the mechanical part is stopped, but it is necessary to always maintain the boosted potential in the state of waiting for operation. . As shown in FIG. 4, the input signal to the external input terminal 101 of the conventional circuit detects the type of button which button has been pressed. Detect by comparing with. Since the reference voltage is generated based on V _DD , first, a start signal is input to the external input terminal 102, the power supply voltage is boosted to V _DD , and then a signal representing the button type is input to the external input terminal 1.
01 must be entered. For this reason, it was necessary to operate the software in order as described above to perform the processing. Alternatively, since V _CC is not used as the reference voltage, fluctuations in a plurality of potentials of the external input terminal 101 must be detected by another external circuit or the like. However, there are problems such as an increase in the number of manufacturing steps. [0014] As described above,
In the conventional portable for IC, battery is used as the power supply voltage V _CC, when the power supply voltage is low, particularly CM
Various circuits are driven by V _{DD which is} boosted from V _CC as a power supply for the OS circuit and the like. Therefore, in order to suppress the consumption of the battery, the boosting of _VDD is stopped while the operation of the mechanical drive unit is stopped, and the booster circuit is activated and the subsequent control operation is performed when necessary. The conventional circuit receives an external input signal assigned to various function buttons, uses a comparator for detecting a plurality of potentials for detecting the type of the button that has been pressed, and uses a reference voltage. However, since only V _DD was used as the reference voltage, a start signal for starting the booster circuit was input, the battery voltage was boosted to V _DD , and then assigned to various function buttons. External input signal must be input to another input terminal. For this reason, a terminal for inputting a start signal and a terminal for inputting a function signal are required separately, and in addition, it is necessary to sequentially operate the above operations on software to perform processing. Alternatively, since only _VDD is used as the reference voltage, it is necessary to detect a variation in a plurality of potentials of the external input terminals assigned to various function buttons by another external circuit or the like. There are problems such as an increase in the cost, installation area, and manufacturing process of the external circuit. An object of the present invention is to solve the above problem by using a battery power source which has not been used as a power source for function control in the conventional method as a power source for a comparison circuit before boosting of a booster circuit is completed. After the boosting, the boosted voltage is used as a power supply for the comparison circuit. This eliminates the need for a conventional dedicated input for starting the IC.
An object of the present invention is to provide a semiconductor device which is improved in cost and installation area on a chip of a semiconductor device by eliminating processing on software or an external circuit. A semiconductor device according to the present invention includes a booster circuit for boosting a power supply voltage, a signal input terminal,
Before the boosting of the boosting circuit, the voltage rises through the first transistor.
The power supply voltage is supplied, and after the boosting of the boosting circuit is completed.
The boosted voltage of the booster circuit is increased via the second transistor.
A comparator for detecting a signal supplied from the signal input terminal.
Before the boosting of the boosting circuit.
Data as a start signal to the booster circuit.
It is characterized by being supplied . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described here. Absent. The following embodiments can be variously changed. An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a circuit diagram showing a first embodiment of the present invention. First, the circuit diagram of FIG.
The outline will be described with reference to the schematic diagram of FIG. As shown in FIG. 2, there is an external input button 9 composed of a plurality of control buttons, a semiconductor set 18 including a comparison circuit is connected to the button 9, and an IC 15 including a booster circuit is connected to the semiconductor set 18. It is connected. First, a button 9, for example, a start button, is pressed to start the semiconductor device. The output signal from the start button unit at that time is a voltage for switching the output of the input determination device 11 at the subsequent stage, for example, V _CC , and is immediately sent to the input determination device 11. The major difference from the prior art at this time is that the power supply voltage V _CC 10 is not applied until the button 9 is pressed, and the power consumption is kept to a minimum. Next, the input determination device 11 determines whether the button 9 has been pressed or not. In the input determination device 11, a button valid for circuit activation (if a button set as an invalid button for circuit activation is pressed, the input determination device 11 determines that the button is invalid, and When the IC circuit 15 including the circuit is not activated, the activation instruction signal is sent to the terminal 17 of the IC circuit 15 and the IC circuit 15 is activated. Next, a signal is sent to the button type determination device 13 for the first time. In the button type determination device 13,
Determine which button was pressed. Only when the valid button is pressed, a function command expressing a signal of a function assigned to the pressed button is sent to the terminal 16 of the IC circuit 15 to execute various functions. Next, the circuit diagram of FIG. 1 will be described. As shown in FIG. 1, an external input terminal 1 function signal (corresponding to a terminal for receiving a signal from the button 9 in the semiconductor set 18 of FIG. 2) is input, through the transistor Q ₁ which is turned on by a separate hold signal V _CC
(Power supply voltage) 8 (corresponding to a battery or the like in the case of a portable device) is the first comparator 3 constituting the comparison circuit
And the second comparator 4 (the button type determination device 1 in FIG. 2)
3) and applied to its peripheral circuits. Although only two comparators are shown in FIG. 1, it goes without saying that three or more comparators can be connected according to the number of functions to be determined. In FIG. 1 according to the present invention, there is no input signal terminal 101 (see FIG. 4) dedicated to activation used in the prior art, and the external input terminal 1 is allocated to various buttons by allocation. 4 can be equivalent to the input signal terminals 101 and 102 of FIG. Therefore, in the first embodiment of the present invention, any button (including all function keys and the like) can be pressed so as to correspond to the input signal 1. In addition, if necessary, determine the signal from the separately installed start button,
Only when the button specified as the start button is pressed, the boost start signal and the control signal A can be generated. When the boosting start signal 5 is input, the boosting
Path 2 is activated and a boosted voltage V _DD is created. In addition,
Before boosting, the input signal assigned to the various buttons is input to the terminal 1, the comparator 3, the power supply
The comparison of the reference voltage produced by using the voltage V _CC 8 is performed, what button has been pressed is determined, as the signal A, the function instruction is issued. [0030] That is, in the embodiment of the present invention, even before the boosted voltage V _DD is created, the V _DD system startup circuit (FIG. 1, a peripheral circuit of the first comparator 3 eighty
The etc.) is adapted to be used in the battery voltage V _CC 8.
Therefore the first comparator 3 signals from the peripheral circuit eighty
A, etc. also you can use before the boost. The hold signal boosted after the end of the booster circuit switches to the hold bar signal, the transistor Q ₁ is becomes blocked <br/> state, while the transistor Q ₂ is turned, the boosted voltage V _DD comparator 3, 4 is applied. As described above, it is possible to form a semiconductor circuit that can operate by inputting a start signal or a function control signal to one input terminal. For this reason, a circuit of a boost power supply system which cannot be used as a start input in the conventional IC can be used as a start input. In addition, a dedicated input terminal for starting, which is required in the conventional IC, is not required, and further, an external circuit for software ranking processing or an electric potential measurement is not required. Improvements such as a reduction in the installation area on the chip were made. Next, a second embodiment of the present invention will be described. The second embodiment of the present invention, as shown in FIG. 3, instead of controlling by both inputs of the circuit of Q ₁ and Q ₂ switching the hold signal and the hold bar signal of Figure 1, the hold signal only It is controlled by the following. In a semiconductor device including a booster circuit for driving, a terminal for booster circuit startup and a terminal for function determination are separately provided in a conventional IC, but a function determination signal and a booster are provided. Since a signal for starting a circuit can be input from the same terminal, a dedicated input terminal for starting is not required unlike a conventional IC. In addition, processing on the software between the signal for activating the booster circuit and the function determination signal is not required, and an external circuit for potential measurement is not required. This is advantageous in the installation area. Further, since there is no need to constantly supply V _CC during standby, power consumption is minimized and a limited power supply voltage of a battery or the like can be used effectively. Further, by controlling the activation of the booster circuit and the function determination by a dedicated IC, the cost can be reduced by a factor of two or more compared to the case where the same function is operated using a microcomputer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a semiconductor device according to a first embodiment of the present invention. FIG. 2 is a schematic view showing a semiconductor device according to the first embodiment of the present invention. FIG. 3 is a circuit diagram showing a semiconductor device according to a second embodiment of the present invention. FIG. 4 is a circuit diagram illustrating an example of a conventional semiconductor device. FIG. 5 is a schematic view illustrating an example of a conventional semiconductor device. FIG. 6 is a configuration diagram of an input button of a conventional semiconductor device. [Description of Signs] 1 ... External input terminals 2, 103 ... Booster circuits 3, 105 ... First comparators 4, 106 ... Second comparators 5, 107 ... Boost start signals 6, 108 ... Hold signals 7 ... Hold bar signals 8, 10, 104: power supply voltage 9, 109: input button 11, 110: input determination device 13, 111: button type determination device 15, 117: IC 16, 114: function instruction 17, 113: IC start instruction 18, 118 ... Chip 101. Input signal terminals 102 assigned to various buttons. External input terminals 115. Signal wiring 116 consuming power of V _CC ... _Wirings R 1, R 1 ′, R 2, and R 2 ′ for button type determination signals. R3, R3 ', R4, R
4 ': resistors Q1, Q2: transistor V _CC ... power supply voltage V _DD ... boosted power supply voltages A, B, C, D ... function command signals assigned to various function buttons E: input signals must be received Signals R5, R6, R7, R8, R9, R10 for transmitting to various places Resistor 119 Activation button 120 Activation terminals 121, 122, 123, and 124 Function buttons

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/822 H01L 27/04

Claims (1)

(57) Claims 1. A booster circuit for boosting a power supply voltage, a signal input terminal, and a first transistor before boosting of the booster circuit.
The power supply voltage is supplied, and after the boosting of the boosting circuit is completed.
The boosted voltage of the booster circuit is increased via the second transistor.
A comparator for detecting a signal supplied from the signal input terminal.
; And a chromatography data, detected by the comparator before the boosting of the booster circuit
A signal is supplied as a start signal to the booster circuit .