JP3468675B2 - Electronics - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic equipment,
More specifically, an electronic device that generates a pulse signal from power whose voltage fluctuates with time to drive a booster circuit and boosts the supplied power, for example, a portable electronic device to which power is supplied from a thermoelectric conversion element or the like. Etc.

[0002]

2. Description of the Related Art Some conventional electronic devices have a power supply device such as a generator or a power supply that supplies electric power whose voltage fluctuates with time. In such an electronic device, in order to enable continuous operation of the drive circuit of the electronic device,
The power supply capability of the power supply device has been set so that it does not fall below the minimum drive voltage of the drive circuit of the electronic device even if the voltage of the power supplied from the power supply device changes with time.

For example, as shown in FIG. 5, a conventional electronic device 50 includes a power supply device 52 that supplies electric power whose voltage fluctuates with time, and an oscillation circuit 54 that outputs a pulse signal.
And a booster circuit 56 that is driven by the pulse signal to boost the power supplied from the power supply device 52, and a booster circuit 5
Rectifying element 5 for rectifying the boosted power output from 6
8 and a storage battery 60 that stores the boosted and rectified electric power.

That is, in the conventional electronic device 50, the power supply device 52 supplies the oscillation circuit 54 and the booster circuit 56 with electric power whose voltage fluctuates with time. Oscillator circuit 5
In 4, the driving is started if the voltage of the power supplied from the power supply device 52 is equal to or higher than the minimum driving voltage of the oscillation circuit 54,
The pulse signal having the predetermined duty ratio is the booster circuit 5.
6 is output. The booster circuit 56 is driven by the pulse signal output from the oscillator circuit 54, and boosts and outputs the power supplied from the power supply device 52.

The boosted electric power is rectified by a rectifying element 58 such as a Schottky diode and charged and stored in a battery 60. The electric power stored in the battery 60 is
It is supplied to an electronic device drive circuit or the like (not shown) and is driven when the supplied voltage is equal to or higher than the minimum drive voltage of the electronic device drive circuit.

As described above, in order to continuously operate the electronic device drive circuit, the electric power of the battery 60 is not emptied, and the electric power output from the battery 60 falls below the minimum drive voltage of the electronic device drive circuit. It was necessary to charge the battery 60 efficiently so that it would not exist.

As the power supply device for supplying the electric power whose voltage fluctuates depending on the above-mentioned time, there are a thermoelectric conversion element and a solar panel which are used for portable electronic equipment and the like whose power consumption is relatively small. For example, a thermoelectric conversion element is a PN junction using P-type and N-type semiconductors, and generates electromotive force by a temperature difference to generate electricity. Therefore, if the temperature difference changes with time, the thermoelectric conversion element is generated accordingly. Electric power (voltage) also changes.

[0008]

In such a conventional electronic device, the electronic device drive circuit continues to operate even if the voltage supplied from the power supply device 52 changes with time. It has been necessary to always charge the battery efficiently and sufficiently so that the voltage supplied to the drive circuit does not fall below the minimum drive voltage.

However, the conventional electronic device 50 shown in FIG.
Then, with the power supplied from the power feeding device 52, the oscillation circuit 54
The booster circuit 5 by the pulse signal from the oscillator circuit.
6, the oscillation circuit 54 is stopped when the voltage of the power supplied from the power supply device 52 is even less than the minimum drive voltage of the oscillation circuit, and when the booster circuit 56 is stopped accordingly, the battery 60 is also charged. It will stop. That is, although the power supply device 52 continues to supply the electric power slightly lower than the minimum drive voltage of the oscillation circuit 54, the charging is stopped, and the electric power is not charged and is wasted. Therefore, there is a disadvantage that the charging time is long and the charging efficiency is very poor.

Therefore, even if the voltage of the electric power supplied from the power supply device 52 fluctuates with time, it is sufficient to set the power supply device 52 with a power supply capacity that does not fall below the minimum drive voltage of the oscillation circuit 54. The power supply device 52 becomes larger,
There is an inconvenience that it cannot be used for portable electronic devices and the like.

Further, instead of setting a large power supply capacity in the power supply device 52, as shown in FIG. 6, a power supply line 72 is connected between the booster circuit 56 and the oscillator circuit 54 and the rectifying element 74 is connected. Provided between the power supply device 52 and the oscillation circuit 54, the power boosted by the booster circuit 56 is supplied to the oscillation circuit 54.
It is also conceivable that the charging efficiency is improved by compensating for the power shortage of the oscillation circuit 54 by returning to the above.

However, since the capacitor 60 having a large capacity is arranged on the output side of the booster circuit 56, the electric power boosted by the booster circuit 56 is charged while the capacitor 60 is not sufficiently charged. As a result, the voltage of the power returned via the power supply line 72 drops,
It is possible that the state of poor charging efficiency will continue.

The present invention has been made in view of the inconveniences of the prior art, and provides an electronic device which can miniaturize a power supply device for supplying electric power and charge a charger with high charging efficiency. The purpose is to do.

[0014]

In order to achieve the above object, an electronic apparatus according to the present invention comprises a power supply means for supplying power whose voltage fluctuates with time, and a pulse signal based on the power supplied from the power supply means. And a booster circuit that is driven by a pulse signal of the oscillator circuit to boost the power supplied from the power supply means, and a storage means that stores the power boosted by the booster circuit. The voltage supplied between the output side and the input side of the oscillation circuit, which is provided between the booster circuit and the storage means, and the power supply line that supplies the power boosted by the booster circuit to the oscillation circuit and the storage means. When the value is less than or equal to the predetermined voltage value, the step-up circuit and the storage means are shut off, and when the voltage value supplied to the storage means exceeds the predetermined voltage value, the electric power boosted by the step-up circuit is stored in the power storage means. Supply to the means A charge control circuit for controlling to electricity, and configured to include a.

According to this, the charge control circuit provided between the booster circuit and the power storage means connects the booster circuit and the power storage means when the voltage value supplied to the power storage means is equal to or less than the predetermined voltage value. When the voltage value supplied to the power storage means exceeds a predetermined voltage value, the voltage is boosted by the booster circuit by shutting off and interrupting charging to prevent a voltage drop of the power supplied to the oscillation circuit via the power supply line. The electric power is supplied to the power storage means to be charged. Therefore, the charging means is charged while keeping the voltage of the electric power supplied to the oscillation circuit constant, so that efficient charging can be performed and the power supply means can be downsized.

Further, a rectifying element for rectifying the electric power supplied from the electric power feeding means is provided between the electric power feeding means and the oscillation circuit, and a rectifying element for rectifying the electric power boosted by the boosting circuit is provided between the boosting circuit and the storage means. The structure is provided between them.

According to this, since the rectifying elements are respectively provided between the power feeding means and the oscillating circuit and between the boosting circuit and the power storing means, the supplied power flows backward through the power supply line or the like to generate the power. It is possible to prevent loss.

The charge control circuit is composed of a MOS transistor of one conductivity type in which the absolute value of the threshold voltage is set to a predetermined voltage value, and the source and drain of the MOS transistor are the input terminal of the charge control circuit. It was assumed that they were respectively connected to the output terminals.

According to this, in the charge control circuit, the MO type of one conductivity type in which the absolute value of the threshold voltage is set to the predetermined voltage value.
Since it is composed of an S transistor, when the potential on the input terminal side of the charge control circuit rises and exceeds the absolute value (predetermined voltage value) of the threshold voltage of the MOS transistor,
The MOS transistor is turned on and power can be sent to the output terminal side of the charge control circuit. Further, when the potential on the input terminal side of the charge control circuit falls and becomes equal to or lower than the threshold voltage, the MOS transistor is turned off, so that the potential on the input terminal side of the charge control circuit is raised again. In this way, the MOS transistor forming the charge control circuit can be charged by sending power to the charging means via the output terminal while keeping the potential on the input terminal side at a predetermined voltage value or higher.

Alternatively, the charge control circuit includes a reference voltage generation circuit that generates the same reference voltage as the predetermined voltage value, a comparison circuit that compares the reference voltage with the input voltage of the charge control circuit, and an input terminal of the charge control circuit. The source and drain are respectively connected to the output terminal and the output terminal, and a MOS transistor of one conductivity type that applies the output signal of the comparison circuit to the gate to perform switching is provided.

According to this, since the charge control circuit is composed of the reference voltage generation circuit, the comparison circuit, and the MOS transistor, the reference voltage generated by the reference voltage generation circuit is changed to change the MOS voltage to an arbitrary predetermined voltage. The transistor can be switched, and electric power can be sent to the charging means through the output terminal to charge while maintaining the potential on the input terminal side of the charge control circuit at a predetermined voltage value or higher.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an electronic device according to the present invention will be described below in detail with reference to the drawings. The electronic device according to the present embodiment supplies electric power for driving an electronic device drive circuit such as a movement of a wristwatch which is a portable electronic device,
The power is supplied from a power supply device using a thermoelectric conversion element and driven.

FIG. 1 shows an electronic device 1 according to this embodiment.
A block diagram showing a schematic configuration of 0 is shown. In FIG. 1, an electronic device 10 is a power feeding device 1 as a power feeding means.
2. Schottky diode 14 as a rectifying element, oscillation circuit 16, booster circuit 18, power supply line 20, charge control circuit 22, Schottky diode 2 as a rectifying element
4. It is composed of a power storage device 26 as a power storage means.

The power supply device 12 uses a thermoelectric conversion element here. In the thermoelectric conversion element, for example, a P-type thermoelectric material element and an N-type thermoelectric material element are sandwiched between two substrates, and the P-type thermoelectric material element and the N-type thermoelectric material element are provided on the substrate via a conductive substance such as metal. PN junction, and a plurality of P, N, P, N, etc. are connected in series.

In this thermoelectric conversion element, when a temperature difference is applied between the PN junction portions, a potential difference (electromotive force) corresponding to the temperature difference is generated, and a high generated voltage is obtained by increasing the PN junctions. be able to. Therefore, the above 2
The time variation of the electromotive voltage when a temperature difference is applied between the substrates is that the voltage rises rapidly immediately after the temperature difference is applied between the thermoelectric conversion elements, but the voltage rises after a certain peak. Goes down and saturates at a certain value.

Immediately after the temperature difference is applied between the substrates, a large voltage can be generated because the applied temperature difference is applied to the thermoelectric conversion element, but as time elapses, the temperature difference between the two substrates is increased. This is because the temperature difference is reduced by heat conduction through the P-type and N-type thermoelectric material elements, and the generated voltage is reduced. Therefore, it is necessary to connect many thermoelectric material elements in series so that a voltage larger than the required voltage value can always be obtained even when the output voltage of the thermoelectric conversion element is saturated. It was necessary to connect more thermoelectric material elements in series because they were sensitive to temperature.

The power output from the power supply device 12 is supplied to the oscillation circuit 16 via the Schottky diode 14 and the booster circuit 18. The power supply device 12 is not limited to the thermoelectric conversion element, and may be a solar panel (solar cell plate) or any other device.

The oscillating circuit 16 generates a pulse signal for driving a booster circuit 18, which will be described later, based on the electric power supplied from the power supply device 12. The oscillator circuit 16 has a minimum drive voltage required to drive it, and unless a voltage higher than this is supplied, the oscillator circuit 16
Does not start driving, and stops driving if the supply voltage falls below the minimum driving voltage during driving. Further, the magnitude of the amplitude of the pulse signal generated by the oscillation circuit 16 increases as the voltage of the power supplied to the oscillation circuit 16 increases. Circuit 1
8 has the effect of improving the boosting efficiency.

The booster circuit 18 is driven by the pulse signal supplied from the oscillator circuit 16 and boosts the voltage of the power supplied from the power supply device 12. When the amplitude of the pulse signal supplied from the oscillation circuit 16 increases,
Since the boosting efficiency is improved, the power supplied from the power supply device 12 can be boosted higher.

The power supply line 20 connects the output terminal of the booster circuit 18 and the power input terminal of the oscillator circuit 16, and even if the power supplied from the power supply device 12 is below the minimum drive voltage of the oscillator circuit 16, Since the power boosted by the booster circuit 18 is supplied to the oscillator circuit 16, the oscillator circuit 16 can be continuously driven. Further, when the voltage supplied to the oscillator circuit 16 becomes high, the amplitude of the pulse signal supplied from the oscillator circuit 16 becomes large, and the boosting efficiency in the booster circuit 18 can be improved.

The charge control circuit 22 is arranged between the booster circuit 18 and the charger 26. When the output voltage of the booster circuit 18 is equal to or lower than the barrier voltage value Va as a predetermined voltage value, electric power is sent to the condenser 26. Shut off so that there is no booster circuit 18
The electric potential of the electric power supplied to the oscillation circuit 16 from the electric power supply line 20 via the electric power supply line 20 is maintained at the barrier voltage, and when the barrier voltage value Va exceeds, the output voltage of the booster circuit 18 is sent to the capacitor 26 to be charged. Therefore, efficient charging control is performed.

In the battery 26, the electric power boosted by the boosting circuit 18 is supplied to the charging control circuit 22 and the Schottky diode 2.
When input via 4, the battery is charged and stored. By supplying the electric power stored in the battery 22 to an electronic device drive circuit (not shown) (here, a wristwatch movement or the like), the electronic device can be driven.

The Schottky diodes 14 and 24 are provided between the power supply device 12 and the oscillation circuit 16 and the charge control circuit 22.
It is provided between the power storage device 26 and the electric storage device 26, and prevents the supply power from flowing backward through the power supply line 20 and the like to cause power loss.

Next, the charge control circuit 22 which is a characteristic configuration of the present embodiment will be described in detail. In the charge control circuit 22, the output voltage of the booster circuit 18 is the barrier voltage value V
In the case of a or less, the power is cut off so as not to send it to the storage battery 26, and the input terminal of the charging control circuit 22 (see FIGS.
32), that is, the output voltage of the booster circuit 18 is kept at a potential equal to or higher than the barrier voltage value Va. When the output voltage of the booster circuit 18 exceeds the barrier voltage value Va, the output voltage of the booster circuit 18 is sent to the capacitor 26 to be charged.

Here, if the above barrier voltage value Va is too low, the amplitude of the pulse signal output from the oscillation circuit 16 to the booster circuit 18 becomes small, and the boosting efficiency of the booster circuit 18 decreases. On the contrary, when the barrier voltage value Va is increased, the amplitude of the pulse signal of the oscillation circuit 16 is increased and the boosting efficiency of the booster circuit 18 is improved, but the charging time is lengthened for the following reasons. .

That is, the current sent to the battery 26 is
A voltage (Vm-Va) obtained by subtracting the barrier voltage value Va from the maximum capacity voltage Vm determined by the characteristics of the power supply device 12 and the booster circuit 18.
Only the current corresponding to is sent to the battery 22. Therefore, as the barrier voltage value Va increases, (Vm-Va) decreases and the electric power sent to the battery 22 decreases, so that the charging time increases. Therefore, the barrier voltage value V
The optimum value a is equal to or less than the maximum capacity voltage Vm determined by the characteristics of the power supply device 12 and the booster circuit 18, and the point that the charging time is the shortest.

Various configurations are conceivable for the charge control circuit 22, but in the present embodiment, the configuration shown in FIGS.
The specific example is shown in FIG.

In the charge control circuit 22 shown in FIG. 2, P
By using the characteristics of the transistor by using the MOS transistor 30, the switching operation at the barrier voltage value Va is realized.

As shown in FIG. 2, the charge control circuit 22
Connects the source (S) of the PMOS transistor 30 to the input terminal 32, connects the drain (D) to the output terminal 34, and sets the gate (G) to the ground (hereinafter, GND) potential. Then, when manufacturing the PMOS transistor 30, channel doping is set so that the absolute value of the threshold voltage of the transistor becomes the barrier voltage value Va.

With this configuration, the voltage on the input terminal 32 side of the charge control circuit 22 rises and the absolute value of the threshold voltage of the PMOS transistor 30 (barrier voltage value V
When a) is exceeded, the transistor is turned on, electric power is sent to the output terminal 34 side of the charge control circuit 22, and the capacitor 2
Charged to 6. If electric power is sent from the input terminal 32 side of the charge control circuit 22 to the output terminal 34 side as it is and charging continues, the potential on the input terminal 32 side drops and the PMOS transistor 30 turns off when the potential becomes equal to or lower than the barrier voltage value Va. , The potential on the input terminal 32 side rises again.

Therefore, the charge control circuit 22 of FIG. 2 can efficiently charge the capacitor 26 by sending electric power to the output terminal 34 side while keeping the potential on the input terminal 32 side at the barrier voltage value Va or more.

Further, while the barrier voltage value Va in FIG. 2 is determined by the threshold voltage of the PMOS transistor 30, FIG.
The charge control circuit 22 shown in (1) is configured so that the barrier voltage value Va can be freely set by connecting to the power supply source whose gate potential can be changed.

As shown in FIG. 3, the charge control circuit 22
Is composed of a reference voltage generation circuit 40, a comparator circuit 42 as a comparison circuit, a PMOS transistor 44, etc., and the source (S) of the PMOS transistor 44.
Is connected to the input terminal 32 of the charge control circuit 22, and the drain (D) is connected to the output terminal 34. The reference voltage output from the reference voltage generating circuit 40 is set to the barrier voltage value Va here, and the absolute value of the threshold voltage of the PMOS transistor 44 is arbitrarily set to the barrier voltage value Va or less.

The output voltage of the reference voltage generating circuit 40 is input to the positive terminal of the comparator circuit 42, and the negative terminal is connected to the input terminal 32 of the charging control circuit 22. The output voltage of the comparator circuit 42 is connected to the gate (G) of the PMOS transistor 44. Here, the comparator circuit 52 is provided with a hysteresis of ΔV to exchange power.

With such a configuration, the potential of the input terminal 32 of the charge control circuit 22 and the reference voltage generation circuit 40.
The output potential of the charge control circuit 22 is compared with the output potential of the reference voltage generation circuit 4
When the output voltage of 0 is exceeded, the comparator circuit 42 outputs a signal to turn on the PMOS transistor 44,
Electric power is sent from the input terminal 32 of the charging control circuit 22 to the output terminal 34, and the charger 26 is charged.

If electric power is sent as it is and charging continues, the potential on the input terminal 32 side of the charge control circuit 22 decreases, and the off detection voltage (barrier voltage value Va−
(Hysteresis ΔV), the comparator circuit 42 outputs a signal to turn off the PMOS transistor 44 (due to the hysteresis of the comparator circuit 42) to set the potential on the input terminal 32 side of the charge control circuit 22 to a constant value. The above can hold.

Since the PMOS transistor 44 is used here, the signal for turning on the transistor is GN.
The signal having the D potential and turned off has the potential of the input terminal of the charge control circuit 22.

As described above, in the charge control circuit 22, the MO
By switching using the S transistor,
While maintaining the input voltage of the charge control circuit 22 at a potential equal to or higher than the barrier voltage value Va, electric power is sent to the output terminal 34 side to store the electric power in the capacitor 2
6 can be charged efficiently.

The charging control circuit 2 shown in FIGS. 2 and 3 is used.
Although all of the above-described examples 2 use the PMOS transistor, the NMOS transistor of the opposite conductivity type may be used to configure the same as the above.

FIG. 4 is a line showing the charging efficiency for the battery 26 according to the present embodiment of FIG. 1 (A in FIG. 4) and the charging efficiency for the battery 60 in the comparative example of FIG. 6 (B in FIG. 4). The figure is shown.

Next, the operation will be described. As shown in FIG. 1, the electric power generated by the thermoelectric conversion element of the power feeding device 12 first activates the oscillation circuit 16 to generate a pulse signal, which is output to the booster circuit 18 to output the booster circuit 18. To start. Then, the booster circuit 18 boosts the power supplied from the power supply device 12. Since the boosted power is supplied to the oscillation circuit 16 via the power supply line 20, it is possible to output a pulse signal having a larger amplitude. The booster circuit 18 can boost the voltage more efficiently as the amplitude of the pulse signal from the oscillator circuit 16 increases.

Since the charging control circuit 22 is connected to the output side of the booster circuit 18, power is cut off between the capacitors 26 until the input voltage of the charging control circuit 22 exceeds the barrier voltage value Va. Is not sent, the voltage is increased until the output voltage of the booster circuit 18 reaches the barrier voltage value Va.

When the input voltage of the charge control circuit 22 exceeds the barrier voltage value Va, the input voltage of the charge control circuit 22 is changed to V.
Since the output power of the booster circuit 18 is sent to the capacitor 26 while keeping the voltage at a, the power supplied to the oscillator circuit 16 is maintained at the barrier voltage value Va or higher, and the booster circuit 18 is driven by the pulse signal having a large amplitude. Therefore, the boosting efficiency is maintained and the charging is performed in a good state. For this reason,
This can contribute to shortening the charging time.

As shown in FIG. 4, this embodiment (A)
In the case of, it can be seen that the charging efficiency is significantly improved as compared with Comparative Example (B). For this reason, the power feeding device 12 is configured by a thermoelectric conversion element that supplies power whose voltage fluctuates with time.
Even if the above is configured, since it is sufficient that power that is equal to or higher than the minimum drive voltage of the oscillation circuit 16 can be supplied first, it is possible to configure with a small power supply device 12 and stable power supply is possible. Therefore, the electronic device can be continuously driven stably.

[0055]

As described above, according to the present invention, the power supply device for supplying electric power can be made as small as possible and the charger can be charged with high charging efficiency.

Further, it is possible to prevent the power loss due to the reverse flow of the supplied power.

Further, it is possible to perform efficient charging by sending electric power to the charging means through the output terminal while keeping the potential on the input terminal side of the charging control circuit at a predetermined voltage value or higher.

Further, it is possible to perform efficient charging by sending electric power to the charging means through the output terminal while keeping the potential on the input terminal side of the charging control circuit at a predetermined voltage value or higher.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an electronic device according to an embodiment.

FIG. 2 is a diagram showing a circuit configuration example of a charge control circuit shown in FIG.

FIG. 3 is a diagram showing another circuit configuration example of the charge control circuit shown in FIG. 1.

FIG. 4 is a diagram showing the charging efficiency of the present embodiment and a comparative example.

FIG. 5 is a block diagram showing a schematic configuration of a conventional electronic device.

FIG. 6 is a block diagram showing a schematic configuration of an electronic device for explaining a problem.

[Explanation of symbols]

10 electronic devices 12 Power supply device 14 Schottky diode 16 oscillator circuits 18 Booster circuit 20 power supply lines 22 Charge control circuit 24 Schottky diode 26 Battery 30,44 PMOS transistor 40 Reference voltage generator 42 Comparator circuit

Continuation of front page (56) Reference JP-A-7-131976 (JP, A) JP-A-9-149631 (JP, A) JP-A-6-334119 (JP, A) JP-A-6-98531 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02M 3/00 H01L 35/00 H02M 3/07

Claims (4)

(57) [Claims] 1. A power supply means for supplying power whose voltage fluctuates with time, an oscillator circuit for generating a pulse signal based on the power supplied from the power supply means, and a pulse signal of the oscillator circuit for driving the power supply means. Oite to an electronic apparatus having a booster circuit for boosting the electric power supplied from the unit, and a storage means for storing electric power that is boosted by the booster circuit,
A power supply line that connects the output side of the booster circuit and the input side of the oscillator circuit and supplies the power boosted by the booster circuit to the oscillator circuit, and is provided between the booster circuit and the storage means. , The voltage value supplied to the storage means is the voltage from the supply means.
When the voltage is equal to or lower than a predetermined constant voltage value higher than the pressure , the step-up circuit and the storage means are disconnected from each other, and when the voltage value supplied to the storage means exceeds the predetermined constant voltage value, An electronic device, comprising: a charge control circuit that controls the power storage unit to be charged by supplying electric power boosted by a booster circuit. 2. A rectifying element that rectifies the power supplied from the power feeding means is provided between the power feeding means and the oscillation circuit, and the booster is provided between the booster circuit and the power storage means. The electronic device according to claim 1, further comprising a rectifying element that rectifies the electric power boosted by the circuit. 3. The charge control circuit is composed of a MOS transistor of one conductivity type in which an absolute value of a threshold voltage is set to the predetermined voltage value, and a source and a drain of the MOS transistor are input to the charge control circuit. The electronic device according to claim 1, wherein the electronic device is connected to a terminal and an output terminal, respectively. 4. The charge control circuit includes a reference voltage generation circuit that generates the same reference voltage as the predetermined voltage value, a comparison circuit that compares the reference voltage with an input voltage of the charge control circuit, and the charge control circuit. A source and a drain are respectively connected to an input terminal and an output terminal of the circuit, and a MOS of one conductivity type is applied to perform switching by applying the output signal of the comparison circuit to the gate.
The electronic device according to claim 1 or 2, further comprising: a transistor.