JP2003316452A - Controlled power source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To comprise a controlled power source with discrete parts including a reset circuit of a lower parts count. <P>SOLUTION: The controlled power source is comprised of: a reference power circuit 11 which outputs a reference voltage for setting a predetermined output; a power adjusting circuit 12 in which a transistor Q1 operates according to a control signal to adjust input power to be the predetermined output, and to generate an output voltage; and a control circuit 13 which includes two transistors Q11, Q12 comprising a differential amplifier circuit, and outputs the control signal to a base of the transistor Q1 for making the input power to be the predetermined output, while inputting the reference voltage and the output voltage. A terminal for the collector of the transistor Q12 inputs the output voltage to the base thereof. The terminal practically prevents a current from flowing when the output voltage decreases to or below a lower limit voltage value lower than the reference voltage by a predetermined voltage, and is set at least as a terminal for a signal source for a reset signal. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control power supply which adjusts an input power supply so as to have a predetermined output and outputs it to a microcomputer or the like which needs to give a reset signal when the output falls below an operable voltage. It is about.

[0002]

2. Description of the Related Art FIG. 11 shows a schematic configuration of a conventional control power source and an example of its use. The control power supply 1 of FIG. 11 is used for a load 4 including a microcomputer 40 that needs to give a reset signal when the output from the control power supply 1 falls below an operable voltage, and a power supply path to this load 4 is provided. It is a series regulator in which the transistor Q1 is arranged in series. That is, the operational amplifier 10 that outputs a control signal in accordance with the difference between the reference voltage Vref1 and the output voltage Vout, and the amplifying operation in accordance with the control signal of the operational amplifier 10 causes the input power from the input power source 3 such as a battery. It is composed of a transistor Q1 which adjusts a fluctuating input voltage Vin to a predetermined output to obtain an output voltage Vout. A switching regulator that uses a transistor as a switching element may be used as the control power source instead of the series regulator.

In FIG. 11, the reset circuit 2 is further incorporated because the load 4 includes the microcomputer 40. The reset circuit 2 inputs the output voltage Vout of the control power supply 1 and another reference voltage Vref2 to the non-inverting input terminal and the inverting input terminal, respectively, and outputs the output voltage Vout.
If the voltage exceeds the reference voltage Vref2, the High signal is output to the microcomputer 40 as a reset release signal, while the output voltage Vref
If out is below the reference voltage Vref2, the comparator 20 is configured to output a Low signal as a reset signal to the microcomputer 40 (see FIG. 12).

According to the control power supply having such a configuration, it is possible to stably supply the power to the load even if the input voltage from the input power supply fluctuates, and reset when the output is lower than the operable voltage. A signal can be given to the microcomputer.

[0005]

However, as shown in FIG.
In the control power supply of JP-A-2005-53662 and the stabilized power supply circuit described in Japanese Patent Application Laid-Open No. 5-53662, a circuit including an operational amplifier for stabilization control is required, and a reset circuit (reset signal generation circuit section) is separately provided. Therefore, it is necessary to further use a comparator or the like for the reset circuit.

Particularly, in a severe environment such as a vehicle,
When the reset circuit is incorporated as another circuit block as described above, the cost of the comparator and the IC for specific functions is increased in addition to the operational amplifier.

[0007] In order to withstand a harsh use environment, it is possible to form each of them with discrete parts, but if there are two circuits in terms of circuitry, the number of parts will increase and the cost will rise as in the above case.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control power supply which can be configured with discrete components having a smaller number of components including a reset circuit.

[0009]

According to a first aspect of the present invention, there is provided a control power supply comprising: a reference power supply circuit for outputting a reference voltage for a predetermined output setting; and a semiconductor element having an amplifying function. This semiconductor element includes a power supply adjusting circuit that adjusts the input power supply to the predetermined output to output by operating the semiconductor element according to a control signal, and a differential amplifier circuit having an amplifying function. The semiconductor device includes one semiconductor element, and inputs the reference voltage and the output of the power supply adjusting circuit to these two semiconductor elements, respectively, and outputs the output of the power supply adjusting circuit when the voltage of this output becomes lower than the reference voltage. A signal for increasing the voltage is output to the semiconductor element of the power supply adjusting circuit as the control signal, while the output of the power supply adjusting circuit is decreased when the voltage of the output is higher than the reference voltage. A control circuit that outputs a signal to the semiconductor element of the power supply adjusting circuit as the control signal, and outputs the output of the power supply adjusting circuit to the first terminal of the two semiconductor elements of the differential amplifier circuit configuration. The second terminal of the semiconductor element is a terminal of a signal source for at least a reset signal.

According to a second aspect of the present invention, in the control power supply according to the first aspect, a reset circuit is further incorporated, and the terminal of the signal source has a lower limit at which the output voltage is lower than the reference voltage by a predetermined voltage. The reset circuit receives from the terminal of the signal source a signal indicating that the voltage of the output has dropped below the lower limit voltage value, which is a terminal at which current does not substantially flow when the voltage drops below the voltage value. The reset signal is output when the reset signal is output, and the reset release signal is output when the signal indicating that the output voltage exceeds the lower limit voltage value is received.

According to a third aspect of the present invention, in the control power supply according to the first aspect, a reset circuit is further incorporated, and the lower limit of the output voltage of the signal source terminal is a predetermined voltage lower than the reference voltage. The reset circuit has a latch function, which is a terminal at which a current does not substantially flow when the voltage drops below a voltage value.
While the reset release signal is output from the terminal of the signal source until the signal indicating that the voltage of the output has dropped to the lower limit voltage value or less is received, the voltage of the output from the terminal of the signal source is the lower limit. It is characterized by outputting a reset signal when receiving a signal indicating that the voltage has dropped below the voltage value.

According to a fourth aspect of the present invention, in the control power source according to the third aspect, the reset circuit outputs the reset release signal when the voltage value of the input power source exceeds a predetermined threshold voltage value. The latch function is set as described above.

According to a fifth aspect of the present invention, in the control power source according to the third aspect, in the reset circuit, a value of a difference between a voltage of the input power source and an output of the power source adjusting circuit exceeds a predetermined voltage value. At this time, the latch function is set so as to output the reset release signal.

According to a sixth aspect of the present invention, in the control power source according to the third aspect, the reset circuit is configured to operate when the difference between the voltage of the input power source and the reference voltage exceeds a predetermined voltage value. The latch function is set so as to output a reset release signal.

According to a seventh aspect of the present invention, in the control power source according to any of the third to sixth aspects, the latch function is provided by a thyristor or a latch circuit composed of a plurality of transistors whose operation is equivalent to that of the thyristor. It is characterized by

According to an eighth aspect of the present invention, in the control power source according to the seventh aspect, the latch circuit sets a value of a difference between a voltage of the input power source and an output of the power source adjusting circuit or a voltage of the input power source. It is characterized by including a function of monitoring a value of a difference from the reference voltage.

According to a ninth aspect of the present invention, in the control power source according to any one of the first to eighth aspects, a starting circuit for starting the control circuit is further incorporated, and the reset circuit outputs a reset release signal. At this time, the starting circuit is equivalently disconnected.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram of a control power supply according to a first embodiment of the present invention.

The control power supply 1a according to the first embodiment is used for a load including a microcomputer that needs to give a reset signal when the output from the control power supply 1a falls below the operable voltage. As shown, the reference power supply circuit 1
1, a power supply adjusting circuit 12, a control circuit 13, and a reset circuit 2a.

The reference power supply circuit 11 is a DC power supply circuit which outputs a reference voltage Vref for setting a predetermined output. The power supply adjustment circuit 12 uses a transistor (bipolar transistor in FIG. 1) Q1 as a semiconductor three-terminal element having an amplification function.
This transistor Q1 performs an amplifying operation in accordance with a control signal (“differential amplified output” in the figure) from the control circuit 13, so that an input voltage Vin from an input power source (not shown) is included.
The output voltage Vout
And In FIG. 1, the circuit configuration of the series regulator is such that the emitter and collector of the transistor Q1 serve as the input terminal and the output terminal of the control power supply 1a, respectively.

The control circuit 13 includes transistors Q11 and Q12 as two semiconductor three-terminal elements having a differential amplifying circuit configuration and having an amplifying function. The transistors Q11 and Q12 are provided as inverting input terminals and non-inverting input terminals of the differential amplifying circuit. When the reference voltage Vref and the output voltage Vout are directly or indirectly input, respectively, and when the output voltage Vout becomes lower than the reference voltage Vref, a signal for increasing the output of the power supply adjusting circuit 12 is used as the control signal of the transistor Q1. On the other hand, when the output voltage Vout becomes higher than the reference voltage Vref while outputting to the base, a signal for lowering the output of the power supply adjusting circuit 12 is output to the base of the transistor Q1 as the control signal.

A feature of the first embodiment is that, of the transistors Q11 and Q12, the output voltage Vout is the collector terminal of the transistor Q12 that inputs the output voltage Vout of the power supply adjusting circuit 12, and the output voltage Vout is the reference voltage Vref. The terminal at which a current does not substantially flow when the voltage drops below a lower limit voltage value lower than a predetermined voltage is at least a terminal of a signal source for a reset signal, and the terminal of the signal source is, for example, a reset circuit including discrete components. It is connected to the input terminal of 2a.

Thus, the output voltage Vout is equal to the reference voltage Vout.
If the terminal at which current does not substantially flow when the voltage drops below the lower limit voltage value that is lower than ref by a predetermined voltage is the terminal of the signal source for the reset signal, depending on the presence or absence of current (collector current) at this terminal, It is possible to determine whether the output voltage Vout is stabilized at a predetermined output. By configuring the terminal of the signal source to be connected to the input terminal of the reset circuit 2a, the reset circuit 2a can be designed to output the reset signal according to the signal obtained from the terminal of the signal source. In addition, the control power supply 1a can be configured with a discrete component including a smaller number of components including the reset circuit 2a.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
It is a block diagram of the control power supply of embodiment.

As shown in FIG. 2, the control power supply 1b of the second embodiment includes a reference power supply circuit 11 and a power supply adjusting circuit 12 similar to those of the first embodiment, and a control circuit as a specific circuit example of the first embodiment. 13a and the reset circuit 2b.

The control circuit 13a includes a differential amplifier circuit similar to that of the first embodiment, which includes transistors Q11 and Q12 whose emitters are connected to each other, and a signal source circuit.
This signal source circuit includes a resistor R130 whose one end is connected in series with the collector of the transistor Q12, and a resistor R13.
A transistor Q13 whose base and emitter are connected to one end and the other end of 0, respectively, and output voltage Vou
When t exceeds a lower limit voltage value that is a predetermined voltage lower than the reference voltage Vref, current is supplied from the collector of the transistor Q13 to the subsequent stage, while the output voltage Vout is equal to the reference voltage Vref.
When the voltage drops below the lower limit voltage value lower than the ref by a predetermined voltage, the supply of the current from the collector of the transistor Q13 to the subsequent stage is stopped.

The reset circuit 2b includes a transistor Q13.
Of the resistor R20, one end of which is connected to the collector of the transistor R20, the other end of which is connected to the base of the transistor Q20, and the base of the transistor Q20.
Resistor R21 connected between emitters and power supply adjustment circuit 1
2 has a resistor R22 connected between the output terminal of the transistor Q20 and the collector of the transistor Q20, and a grounded-emitter transistor Q connecting the collector and base of the transistor Q20.
21, the output terminal of the power supply adjusting circuit 12 and the transistor Q
21 and a resistor R23 connected to the collector of the transistor 21, and the collector of the transistor Q21 is used as a reset output terminal. That is, the current amplifying circuit is configured by the transistor Q20 and the like, and
When the current is supplied from the collector of the transistor Q13 to the input of the current amplification circuit (the base side of the transistor Q20) from the collector of the transistor Q13, the output of the inverting circuit (terminal of the reset output) is High.
It becomes a level, and if not so, it becomes a Low level.

In the control power supply 1b having the above structure, the output voltage V
When out is stabilized to a predetermined output, collector current flows in both transistors Q11 and Q12, so
The collector current of the one transistor Q12 flows through the resistor R130 between the emitter and base of the transistor Q13, so that the current flows through the collector of the transistor Q13 and the current is supplied to the input of the current amplification circuit in the reset circuit 2b. Will be. As a result, the reset output terminal of the reset circuit 2b becomes High level,
A reset release signal will be output.

On the other hand, when the output voltage Vout drops below the lower limit voltage value which is lower than the reference voltage Vref by a predetermined voltage, the collector current substantially does not flow into the transistor Q12 (becomes substantially zero). Also, no collector current flows, and no current is supplied to the input of the current amplification circuit in the reset circuit 2b. As a result, the reset output terminal of the reset circuit 2b becomes Low.
The level becomes the level and the reset signal is output.

As described above, according to the second embodiment, the control power supply 1b can be constituted by the discrete components including the reset circuit 2a and having a smaller number of components.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
It is a block diagram of the control power supply of embodiment.

As shown in FIG. 3, the control power supply 1c of the third embodiment has a power supply adjusting circuit 12 and a reset circuit 2b similar to those of the second embodiment, and a reference power supply circuit as a specific circuit example of the second embodiment. 11a and the control circuit 13b.

The reference power supply circuit 11a has a resistor R110 having one end connected to a terminal for inputting an input voltage Vin from an input power supply (not shown), and a cathode and an anode connected to the other end of the resistor R110 and a GND terminal, respectively. And a Zener diode ZD11, and the input voltage Vin is received by the Zener diode ZD11 via the resistor R110, and this Zener voltage is output as the reference voltage Vref.

The control circuit 13b includes resistors R131 and R13.
2, a voltage divider circuit, transistors Q11, Q12 and a resistor R133, a differential amplifier circuit, and a transistor Q.
13 and a resistor R130. The voltage divider circuit is the power supply adjustment circuit 1
A resistor R131 having one end connected to the second output terminal and a resistor R132 connected between the other end of the resistor R131 and the GND terminal. The voltage across the resistor R132 is the output voltage of the power supply adjustment circuit 12. Output as a divided voltage of Vout.

In the differential amplifier circuit, the collector is connected to the base of the transistor Q1 and the reference voltage Vref is input to the base, and the collector is connected to the terminal to which the input voltage Vin is input via the resistor R130. A transistor Q12 for inputting a voltage to the base and a resistor R133 connected between both emitters of these transistors Q11 and Q12 and the GND terminal are included, and a control signal is applied to the base of the transistor Q1 in the same manner as in the first embodiment. Output. In a basic differential amplifier circuit, a current source is generally used for the resistor R133 portion, but during stabilization control, the emitter voltage does not fluctuate significantly, so
There is no problem with resistance.

In the configuration of this differential amplifier circuit, the input voltage V
in serves as a power supply, the collector current of the transistor Q11 serves as a differential amplification output, and the power supply adjusting circuit 12 serves as a control signal.
Control transistor Q1.

The reference voltage Vref is applied to the base of the transistor Q11, while the divided voltage of the output voltage Vout is applied to the base of the transistor Q12. Therefore, theoretically, Vout = (1 + R131 / R132) Vref is calculated. Output voltage Vout is controlled.

Ignoring the base-emitter voltage of the transistor Q11, the voltage of the resistor R133 becomes the reference voltage Vref.
When the output voltage Vout decreases, the collector current of the transistor Q11 increases so as to maintain the voltage of the resistor R133 at the reference voltage Vref, so that the base current of the transistor Q1 increases and the transistor Q1 increases.
Collector current increases, and the output of the power supply adjusting circuit 12 increases.

On the contrary, when the output voltage Vout increases, the collector current of the transistor Q12 increases and the collector current of the transistor Q11 decreases, so that the base current of the transistor Q1 decreases and the collector current of the transistor Q1 decreases. Then, the output of the power supply adjusting circuit 12 decreases.

The operation of the signal source circuit in the control circuit 13b is the same as that of the second embodiment. For example, the output voltage Vou
When t falls below the lower limit voltage value which is lower than the reference voltage Vref by a predetermined voltage, the emitter becomes higher in potential than the base in the transistor Q12, the base current stops flowing, and the transistor Q12 is turned off. No longer flow to.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment according to the present invention.
FIG. 5 is a configuration diagram of a control power supply of the embodiment, and FIG. 5 is an explanatory diagram of a reset release signal output command and a reset signal output command used in the control power supply.

As shown in FIG. 4, the control power supply 1d of the fourth embodiment has the same reference power supply circuit 11 as that of the first embodiment.
The power supply adjustment circuit 12 and the control circuit 13, the input power supply monitoring circuit 14 not in the first embodiment, and the reset circuit 2c different from the first embodiment are included.

The input power supply monitoring circuit 14 monitors the input voltage Vin, and when the input voltage Vin exceeds the predetermined voltage value Vi1,
This is a circuit that issues a reset release signal output command. The predetermined voltage value Vi1 is set higher than the voltage value of the predetermined output of the power supply adjusting circuit 12. It is more desirable to set the output voltage Vout higher than the lowest input voltage that allows stable output.

The reset circuit 2c is the input power supply monitoring circuit 1
When a reset release signal output command is received from
While outputting the h-level reset release signal, when the control circuit 13 inputs a signal (reset signal output command) indicating that the output voltage Vout has dropped below the lower limit voltage value Vi2 which is a predetermined voltage lower than the reference voltage Vref, This circuit outputs a low-level reset release signal.

In the control power supply 1d having the above structure, the input voltage V
When in exceeds a predetermined voltage value Vi1, the input power supply monitoring circuit 1
Since a reset release signal output command is issued from 4 to the reset circuit 2c, a high level reset release signal is output from the reset circuit 2c. Thereafter, when the reset signal output command is issued from the control circuit 13 to the reset circuit 2c, the reset release signal of Low level is output from the reset circuit 2c.

As described above, by using the predetermined voltage value Vi1 in addition to the lower limit voltage value Vi2, the output signal of the reset circuit 2c can be provided with hysteresis, so that the reset signal and the reset release signal can be combined with each other. Stable output is possible.

(Fifth Embodiment) FIG. 6 shows a fifth embodiment of the present invention.
It is a block diagram of the control power supply of embodiment.

As shown in FIG. 6, the control power supply 1e of the fifth embodiment includes a power supply adjusting circuit 12 and a control circuit 13b similar to those of the third embodiment, and an input power supply monitoring circuit 14a not included in the third embodiment. , A reference power supply circuit 11b and a reset circuit 2d different from those of the third embodiment.

The input power supply monitoring circuit 14a monitors the input voltage Vin, similarly to the input power supply monitoring circuit 14 of the fourth embodiment, and when the input voltage Vin exceeds the predetermined voltage value Vi1, a reset release signal output command is issued. This is the output circuit, and the Zener diode ZD14 is used in FIG.

The reference power supply circuit 11b is different from the reference power supply circuit 11a of the third embodiment in that the connection point of the resistor R110 and the Zener diode ZD11 and the power supply adjustment circuit 1 are different.
The resistor R111 connected between the second output terminal and the second output terminal is further included.

Similar to the reset circuit 2b of the third embodiment, the reset circuit 2d includes transistors Q20 and Q21 and resistors R20 to R23, and an anode and a cathode are connected to the other end of the resistor R20 and the base of the transistor Q20, respectively. Thyristor Q22, a resistor R24 connected between the cathode and gate of the thyristor Q22, and a resistor R25 connected between the gate of the thyristor Q22 and the output of the input power supply monitoring circuit 14a. There is.

Thyristor Q2 in this reset circuit 2d
Since the reset circuit 2d has the hysteresis described in the fourth embodiment, the output voltage Vout from the control circuit 13b has dropped to the lower limit voltage value Vi2 lower than the reference voltage Vref by a predetermined voltage or less. It is provided as a latch circuit that holds the output state according to the reset release signal output command from the input power supply monitoring circuit 14a until the signal (reset signal output command) indicating is input.

In the control power supply 1e having the above structure, the input voltage V
When in starts to rise from around zero, transistor Q13
Is in the off state, the reset signal output command is issued from the transistor Q13 to the reset circuit 2d.

After that, when the input voltage Vin rises and the output voltage Vout becomes stable, a current is supplied from the transistor Q13 to the reset circuit 2d as a signal indicating that. At this time, in the third embodiment, the reset release signal is output from the reset circuit, but in the fifth embodiment, since the thyristor Q22 is in the off state, the reset signal is continuously output from the reset circuit 2d. become.

After that, when the input voltage Vin further rises and exceeds the Zener voltage of the Zener diode ZD14, a current as a reset release signal output command flows from the Zener diode ZD14 to the gate of the thyristor Q22 to turn on the thyristor Q22. Become. As a result, current is supplied from the transistor Q13 to the reset circuit 2d, and the reset release signal is output from the reset circuit 2d.

After that, if the input voltage Vin starts to drop and falls below the Zener voltage of the Zener diode ZD14, the current as the reset release signal output command becomes zero, but the current is supplied from the transistor Q13 to the reset circuit 2d. Therefore, the reset release signal is continuously output from the reset circuit 2d.

After that, when the input voltage Vin drops and a reset signal output command is issued from the transistor Q13 to the reset circuit 2d (when current is no longer supplied from the transistor Q13 to the reset circuit 2d), the thyristor Q22.
Is turned off, and a reset signal is output from the reset circuit 2d.

By the way, in the reference power supply circuit 11b,
Since the stable output voltage Vout of the power supply adjusting circuit 12 is further superimposed on the Zener diode ZD11, the stability of the reference voltage Vref obtained from the Zener diode ZD11 is improved. If the resistor R110 is not provided, the resistor R11
If only 1 is provided, the circuit does not operate even if the input voltage Vin rises from the state where the output voltage Vout is zero. Therefore, the resistor R110 is used as a component of the starting circuit. In this case, by setting the resistance values such that R111 <R110, it is possible to suppress the influence of the fluctuation of the input voltage Vin that affects the reference voltage Vref.

(Sixth Embodiment) FIG. 7 shows a sixth embodiment according to the present invention.
It is a circuit diagram of a reset circuit and an input voltage monitoring circuit for configuring the control power supply of the embodiment.

The control power supply of the sixth embodiment differs from that of the fifth embodiment in that the reference power supply circuit 11b, the power supply adjusting circuit 12, the control circuit 13b and the input power supply monitoring circuit 14a are the same as those in the fifth embodiment. The reset circuit 2e shown in FIG.

In the reset circuit 2e, the thyristor Q22 in the reset circuit 2d of the fifth embodiment is replaced by the transistor Q2.
It has a circuit configuration in which 0 and Q23 are substituted. The elements are arranged in terms of transistors Q20 and Q21 and a resistor R2.
In addition to including 0 to R25, the transistor Q23 and the diodes D20 and D21 are included. In terms of a circuit, the transistor Q20 in the fifth embodiment is also used as a substitute part for the thyristor. The diodes D20 and D21 are arranged in order to prevent the current from the transistor Q13 from flowing into the transistor Q21. Even with such a configuration, the circuit operation is similar to that of the fifth embodiment.

(Seventh Embodiment) FIG. 8 shows a seventh embodiment according to the present invention.
It is a block diagram of the control power supply of embodiment.

As shown in FIG. 8, the control power supply 1f of the seventh embodiment has a power supply adjusting circuit 12 and a control circuit 13b similar to those of the sixth embodiment, and a reference power supply circuit 11c and a reset different from those of the sixth embodiment. And a circuit 2f.

The reference power supply circuit 11c is different from the reference power supply circuit 11b of the sixth embodiment in that the connection point of the resistor R110 and the Zener diode ZD11 and the power supply adjustment circuit 1 are different.
A diode D110, which is connected in series with the resistor R111 and has a cathode connected to the cathode of the Zener diode ZD11, is configured to be connected between the second output terminal and the second output terminal.

The reset circuit 2f includes a transistor Q2
0 and Q23 and resistors R20 to R23 are included as in the reset circuit 2e of the sixth embodiment, and the transistor Q2 is included.
FET (MOS type field effect transistor) Q instead of 1
21a, and a transistor Q2 that forms a latch circuit.
3 is also used as an input voltage monitoring circuit, the input voltage is monitored by the difference between the input voltage and the output voltage, and the base-emitter voltage of the latch circuit has a main hysteresis voltage width.

In the control power supply 1f having the above structure, the output voltage V
When out is stabilized and the transistor Q13 is turned on,
When the latch circuit is in the off state of the thyristor, a voltage substantially equal to the input voltage Vin is applied to the emitter of the transistor Q23. At this time, since the output voltage Vout is applied to the base of the transistor Q23 and the gate of the FET-Q21a, the FET-Q21a is turned on and the reset signal is output.

In the transistor Q23, when the emitter voltage (≈Vin) becomes higher than the output voltage Vout applied to the base by the base-emitter voltage or more, the base current flows, so that the transistor Q23 is turned on and the transistor Q20 is turned on. Become. That is, the latch circuit is turned on. As a result, the transistor Q
Since the base voltage of 23 and the gate voltage of the FET-Q21a decrease and the FET-Q21a turns off, a reset release signal is output. This state is maintained while the current flows from the transistor Q13 to the reset circuit 2f.

By the way, the reference power supply circuit 1 of the fifth embodiment
In 1b, if the impedance of the load connected to the output terminal is small, the resistance 110 may not be as large as the resistance value of the resistance R111. This is because the input voltage Vin is divided by the resistances of the resistors R110 and R111 and the load, but this is prevented by connecting the diode D110 in series with the resistor R111, and the resistor 110 is much more reliable than the resistor R111. The resistance value can be set to a very large value, so that the reference voltage Vref can be stabilized.

(Eighth Embodiment) FIG. 9 shows an eighth embodiment of the present invention.
It is a circuit diagram of a reset circuit for configuring the control power supply of the embodiment.

The control power supply of the eighth embodiment includes a reference power supply circuit 11c, a power supply adjusting circuit 12 and a control circuit 13b similar to the seventh embodiment, and a reset circuit 2g shown in FIG. 9 different from the seventh embodiment. It is composed by.

In the reset circuit 2g, the FET-Q21a
A diode Q21 is used in place of. The diodes D20 and D21 are connected so that the current from the transistor Q13 does not pass through the transistors Q23 and Q23. The output voltage Vout is applied to the base of the diode Q23 via the resistor R27. To widen the hysteresis width, a diode D23 is connected to the emitter of the transistor Q23, and the hysteresis width is widened by the amount of the forward voltage. A Zener diode may be used. And the reset circuit 2
A resistor R26 is provided to divide the input voltage to g. With such a configuration, as in the seventh embodiment, it is possible to stably output the reset signal and the reset release signal by the latch function or the like.

(Ninth Embodiment) FIG. 10 is a block diagram of a control power supply according to a ninth embodiment of the present invention.

As shown in FIG. 10, the control power supply 1h of the ninth embodiment has a power supply adjusting circuit 12 and a control circuit 13b similar to those of the seventh embodiment, and a reference power supply circuit 11d and a reset different from those of the seventh embodiment. And a circuit 2h.

The reference power supply circuit 11d is different from the reference power supply circuit 11c of the seventh embodiment in that the diode D11 is different.
0 is connected in series with the resistor R110 instead of the resistor R111.

The reset circuit 2h differs from the reset circuit 2f of the seventh embodiment in that it includes an FET-Q20a instead of the transistor Q20, and does not monitor the difference between the input voltage Vin and the output voltage Vout. Input voltage V
In order to monitor the difference between in and the reference voltage, the resistor R22 for taking in the output voltage Vout is eliminated and the transistor Q
The reference voltage is taken into the base of 23 and the gate of the FET-Q21a. The reference voltage to the reset circuit 2h is taken from the connection point between the resistor R110 and the diode D110.

The transistor Q of the control power supply 1h having the above structure
23, the input voltage Vin from the transistor Q13
When the voltage difference between the reference voltage and the reference voltage exceeds the voltage between the base and the emitter, the latch circuit (thyristor) including the transistor Q23 and the FET-Q20a is turned on. As a result, the reset release signal is output from the reset circuit 2h.

Transistor Q23 and FET-Q20
When the latch circuit (thyristor) composed of a is turned on, the voltage at the connection point between the resistor R110 and the diode D110 becomes almost zero, and the current supply to the Zener diode ZD11 is stopped, so the Zener voltage is in the reset release state. More stable at. That is, when the starting circuit in the reference power supply circuit 11d is released from reset, the reference power supply circuit 11d is released.
It is separated from d. Other operations are the same as in the seventh embodiment.

In the ninth embodiment, the reset circuit 2
Although h is incorporated in the configuration, the present invention is not limited to this, and the same reset circuit 2g as in the eighth embodiment may be incorporated.

In the reset circuit 2h, the FET-Q
Although 20a is used, it goes without saying that a similar semiconductor element such as a transistor (bipolar transistor) may be used. Conversely, the same applies to the use of FETs (field effect transistors) instead of transistors (bipolar transistors).

Further, in each of the above embodiments, the power supply adjusting circuit is a series regulator, but a switching regulator such as a chopper may be used as long as the control circuit of each embodiment can be used.

[0081]

As is apparent from the above, the control power supply according to the invention of claim 1 includes a reference power supply circuit for outputting a reference voltage for setting a predetermined output and a semiconductor element having an amplifying function, This semiconductor element operates in response to a control signal to adjust the input power supply to the predetermined output to output the power, and two semiconductors having an amplifying function in a differential amplifier circuit configuration. In order to increase the output of the power supply adjusting circuit when the reference voltage and the output of the power supply adjusting circuit are respectively input to these two semiconductor devices, and the voltage of this output becomes lower than the reference voltage. Is output to the semiconductor element of the power supply adjustment circuit as the control signal, and a signal for lowering the output of the power supply adjustment circuit is output when the voltage of the output is higher than the reference voltage. And a control circuit for outputting to the semiconductor element of the power supply adjusting circuit as a control signal, a semiconductor for inputting the output of the power supply adjusting circuit to the first terminal of the two semiconductor elements of the differential amplifier circuit configuration. Since the second terminal of the element is at least the terminal of the signal source for the reset signal, the second terminal is monitored when the semiconductor element of the differential amplifier circuit configuration is, for example, a transistor and the second terminal is the collector. By doing so, it is possible to determine whether the output is stabilized at a predetermined output. Then, by connecting the terminal of the signal source to the input terminal of the reset circuit, the reset circuit can be designed to output the reset signal in accordance with the signal obtained from the terminal of the signal source. The control power supply can be configured with discrete components including a smaller number of components including circuits.

According to a second aspect of the present invention, in the control power source according to the first aspect, a reset circuit is further incorporated, and the lower limit of the output voltage of the signal source terminal is lower than the reference voltage by a predetermined voltage. The reset circuit receives from the terminal of the signal source a signal indicating that the voltage of the output has dropped below the lower limit voltage value, which is a terminal at which current does not substantially flow when the voltage drops below the voltage value. If a signal indicating that the voltage of the output exceeds the lower limit voltage value is received, a reset release signal is output. , It is possible to determine whether the output is regulated to a predetermined output, which makes it possible to control power with discrete components with a smaller number of components including the reset circuit. It can be configured.

According to a third aspect of the present invention, in the control power source according to the first aspect, a reset circuit is further incorporated, and the lower limit of the output voltage of the signal source is lower than the reference voltage by a predetermined voltage. The reset circuit has a latch function, which is a terminal at which a current does not substantially flow when the voltage drops below a voltage value.
While the reset release signal is output from the terminal of the signal source until the signal indicating that the voltage of the output has dropped to the lower limit voltage value or less is received, the voltage of the output from the terminal of the signal source is the lower limit. When a signal indicating that the voltage has dropped below the voltage value is received, a reset signal is output.
Whether or not the output is stabilized to a predetermined output can be determined by the presence / absence of current at the terminal of the signal source, and thus the control power supply is composed of discrete components with a smaller number of components including the reset circuit. be able to.

According to a fourth aspect of the present invention, in the control power source according to the third aspect, the reset circuit outputs the reset release signal when the voltage value of the input power source exceeds a predetermined threshold voltage value. Since the latch function is set as described above, more stable output of the reset signal and the reset release signal becomes possible.

According to a fifth aspect of the present invention, in the control power source according to the third aspect, in the reset circuit, the value of the difference between the voltage of the input power source and the output of the power source adjusting circuit exceeds a predetermined voltage value. At this time, since the latch function is set so as to output the reset release signal, more stable output of the reset signal and the reset release signal becomes possible.

According to a sixth aspect of the present invention, in the control power source according to the third aspect, the reset circuit is configured to operate when the difference between the voltage of the input power source and the reference voltage exceeds a predetermined voltage value. Since the latch function is set so as to output the reset release signal, more stable output of the reset signal and the reset release signal becomes possible.

According to a seventh aspect of the present invention, in the control power supply according to any of the third to sixth aspects, the latch function is provided by a thyristor or a latch circuit composed of a plurality of transistors whose operation is equivalent to that of the thyristor. Therefore, the output signal of the reset circuit can have hysteresis.

According to an eighth aspect of the present invention, in the control power source according to the seventh aspect, the latch circuit sets a value of a difference between a voltage of the input power source and an output of the power source adjusting circuit or a voltage of the input power source. It includes a function of monitoring the value of the difference from the reference voltage, and in any of these configurations, the reset signal and the reset release signal can be output.

According to a ninth aspect of the present invention, in the control power supply according to any one of the first to eighth aspects, a starting circuit for starting the control circuit is further incorporated, and the reset circuit outputs a reset release signal. At this time, since the starting circuit is equivalently disconnected, it is possible to perform a suitable circuit operation in which the starting circuit does not function when reset is released.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control power supply according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a control power supply according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a control power supply according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a control power supply according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram of a reset release signal output command and a reset signal output command used in the control power supply.

FIG. 6 is a configuration diagram of a control power supply according to a fifth embodiment of the present invention.

FIG. 7 is a circuit diagram of a reset circuit and an input voltage monitoring circuit for configuring a control power supply according to a sixth embodiment of the present invention.

FIG. 8 is a configuration diagram of a control power supply according to a seventh embodiment of the present invention.

FIG. 9 is a circuit diagram of a reset circuit for configuring a control power supply according to an eighth embodiment of the present invention.

FIG. 10 is a configuration diagram of a control power supply according to a ninth embodiment of the present invention.

FIG. 11 is a diagram showing a schematic configuration of a conventional control power supply and an example of its use.

FIG. 12 is an explanatory diagram of output signals of the reset circuit in FIG.

[Explanation of symbols]

1a, 1b, 1c, 1d, 1e, 1f, 1h Control power supply 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h Reset circuit 11, 11a, 11b, 11c, 11d Reference power supply circuit 12 Power supply adjusting circuit 13, 13a, 13b Control circuit 14, 14a Input voltage monitoring circuit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5B011 DB02 GG04                 5B054 BB02 DD13 EE03                 5H410 BB02 BB04 CC02 DD02 EA10                       EB16 FF03 FF25 LL04                 5H430 BB01 BB09 BB11 EE03 FF02                       FF13 GG02 HH02 LA04 LB01                       LB02

Claims (9)

[Claims] 1. A reference power supply circuit for outputting a reference voltage for setting a predetermined output, and a semiconductor element having an amplifying function. The semiconductor element operates in response to a control signal, whereby the input power source is set to the predetermined value. A power supply adjusting circuit that adjusts the output to obtain an output, and two semiconductor elements having an amplifying function in a differential amplifier circuit configuration. These two semiconductor elements include the reference voltage and the power supply adjusting circuit, respectively. And a signal for increasing the output of the power supply adjusting circuit is output to the semiconductor element of the power supply adjusting circuit as the control signal when the voltage of the output becomes lower than the reference voltage. When the output voltage becomes higher than the reference voltage, a control circuit that outputs a signal for lowering the output of the power supply adjusting circuit to the semiconductor element of the power supply adjusting circuit as the control signal. Of the two semiconductor elements having the differential amplifier circuit configuration, the second terminal of the semiconductor element that inputs the output of the power supply adjustment circuit to the first terminal is at least the terminal of the signal source for the reset signal. Control power supply characterized by the following. 2. A reset circuit is further incorporated, and current does not substantially flow through the terminal of the signal source when the voltage of the output drops below a lower limit voltage value which is a predetermined voltage lower than the reference voltage. The reset circuit outputs a reset signal when a signal indicating that the voltage of the output has dropped to the lower limit voltage value or less is output from the terminal of the signal source, while the reset circuit outputs the voltage of the output. The reset release signal is output when a signal indicating that the voltage exceeds the lower limit voltage value is received.
Control power supply described. 3. A reset circuit is further incorporated, and current does not substantially flow to the terminal of the signal source when the voltage of the output drops below a lower limit voltage value that is a predetermined voltage lower than the reference voltage. The reset circuit has a latch function, and by this latch function, the reset is released until a signal indicating that the voltage of the output has dropped below the lower limit voltage value is received from the terminal of the signal source. 2. A reset signal is output when a signal indicating that the voltage of the output has dropped below the lower limit voltage value is received from the terminal of the signal source while outputting the signal. Control power supply. 4. The reset circuit sets the latch function so as to output the reset release signal when the voltage value of the input power supply exceeds a predetermined threshold voltage value. 3. Control power supply described in 3. 5. The reset circuit has the latch function to output the reset release signal when a value of a difference between a voltage of the input power supply and an output of the power supply adjusting circuit exceeds a predetermined voltage value. 4. Setting according to claim 3,
Control power supply described. 6. The reset circuit sets the latch function to output the reset release signal when a value of a difference between the voltage of the input power supply and the reference voltage exceeds a predetermined voltage value. The control power supply according to claim 3, wherein 7. The thyristor or a latch circuit composed of a plurality of transistors whose operation is equivalent to that of the thyristor has the latch function.
6. The control power supply according to any one of 1 to 6. 8. The latch circuit includes a function of monitoring a value of a difference between the voltage of the input power supply and an output of the power supply adjusting circuit, or a value of a difference between the voltage of the input power supply and the reference voltage. The control power supply according to claim 7, wherein: 9. The start circuit for starting the control circuit is further incorporated, and when the reset circuit outputs a reset release signal, the start circuit is equivalently disconnected. Control power supply according to any one.