Semiconductor apparatus for power supply control and output voltage variable power supply apparatus

Patent metadata

Field	Value
Publication number	US-11327516-B2
Application number	US-202017061370-A
Country	US
Kind code	B2
Filing date	Oct 1, 2020
Priority date	Apr 3, 2018
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

A power supply control apparatus includes a voltage control transistor connected between a DC voltage input terminal and an output terminal; a control circuit controlling the voltage control transistor according to an output feedback voltage; and a first external terminal receiving an output control signal to control an output voltage. The control circuit includes a first error amplifier outputting a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage; and an output changing circuit including a second error amplifier receiving a voltage input in the first external terminal, a transistor having a control terminal receiving the output of the second error amplifier, and a current mirror circuit connected to the voltage input terminal which transfers an electric current flowing in the transistor. The output changing circuit displaces the divided voltage according to a voltage input at the first external terminal to change the output voltage according to the output control signal.

First claim

What is claimed is:

1. A semiconductor apparatus for power supply control, comprising:
a voltage control transistor connected between a voltage input terminal in which DC voltage is input and an output terminal;
a control circuit which controls the voltage control transistor according to an output feedback voltage; and
a first external terminal in which an output control signal supplied from outside to control an output voltage is input,
wherein the control circuit includes:
a first error amplifier which outputs a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage; and

an output changing circuit which includes a second error amplifier in which a voltage input in the first external terminal is input, a transistor in which an output of the second error amplifier is applied to a control terminal thereof, and a current mirror circuit which is connected to the voltage input terminal and which transfers an electric current flowing in the transistor, wherein the output changing circuit displaces the voltage divided by the first voltage dividing circuit input in the first error amplifier according to a voltage input in the first external terminal to change the output voltage to a voltage according to the output control signal.

2. The semiconductor apparatus for power supply control according to claim 1 , wherein the output changing circuit includes
a resistor element connected in series with a transistor,
wherein the second error amplifier outputs voltage according to an electric potential difference between the voltage input in the first external terminal and a voltage converted by current-voltage conversion by the resistor element to the control terminal of the transistor, flows an electric current according to the electric potential difference in the transistor, and flows, in a node from which the voltage divided by the first voltage dividing circuit is taken out, the electric current transferred in the current mirror circuit.

3. The semiconductor apparatus for power supply control according to claim 1 , further comprising:
a reference voltage source which generates the reference voltage;
a bias circuit which generates an operation electric current supplied to the reference voltage source and the first error amplifier; and
a second external terminal in which a control signal supplied from outside is input to stop an operation of the power supply apparatus,
wherein the bias circuit stops the supply of the operation electric current to the reference voltage source and the first error amplifier according to the control signal input in the second external terminal.

4. An output voltage variable power supply apparatus comprising:
the semiconductor apparatus for power supply control according to claim 1 ; and
a control apparatus which outputs a signal input to the first external terminal or to the first external terminal and the second external terminal,
wherein the output voltage changes according to the signal input from the control apparatus to the first external terminal.

5. The output voltage variable power supply apparatus according to claim 4 , wherein a load connected to the output terminal of the semiconductor apparatus for power supply control is a DC motor.

6. A semiconductor apparatus for power supply control, comprising:
a voltage control transistor connected between a voltage input terminal in which DC voltage is input and an output terminal;
a control circuit which controls the voltage control transistor according to an output feedback voltage; and
a first external terminal in which an output control signal supplied from outside to control an output voltage is input,
wherein the control circuit includes:
a first error amplifier which outputs a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage; and
an output changing circuit which includes a second error amplifier in which a voltage input in the first external terminal is input, a transistor in which an output of the second error amplifier is applied to a control terminal thereof, and a current mirror circuit which is connected to the voltage input terminal and which transfers an electric current flowing in the transistor, wherein the output changing circuit flows the electric current transferred in the current mirror circuit to a node in which the voltage divided by the first voltage dividing circuit is taken out and displaces the voltage divided by the first voltage dividing circuit input in the first error amplifier to change the output voltage.

7. The semiconductor apparatus for power supply control according to claim 6 , further comprising:
a reference voltage source which generates the reference voltage;
a bias circuit which generates an operation electric current supplied to the reference voltage source and the first error amplifier; and
a second external terminal in which a control signal supplied from outside is input to stop an operation of the power supply apparatus,
wherein the bias circuit stops the supply of the operation electric current to the reference voltage source and the first error amplifier according to the control signal input in the second external terminal.

8. An output voltage variable power supply apparatus comprising:
the semiconductor apparatus for power supply control according to claim 6 ; and
a control apparatus which outputs a signal input to the first external terminal or to the first external terminal and the second external terminal,
wherein the output voltage changes according to the signal input from the control apparatus to the first external terminal.

9. The output voltage variable power supply apparatus according to claim 8 , wherein a load connected to the output terminal of the semiconductor apparatus for power supply control is a DC motor.

10. A semiconductor apparatus for power supply control comprising:
a voltage control transistor connected between a voltage input terminal in which DC voltage is input and an output terminal;
a control circuit which controls the voltage control transistor according to an output feedback voltage; and
a first external terminal in which an output control signal supplied from outside to control an output voltage is input,
wherein the control circuit includes:
a first error amplifier which outputs a voltage according to an electric potential difference between a voltage divided by a first voltage dividing circuit which divides the output voltage of the output terminal and a predetermined reference voltage; and
an output changing circuit which includes a second error amplifier in which voltage input in the first external terminal is input, a transistor in which an output of the second error amplifier is applied to a control terminal thereof, and a current mirror circuit which is connected to the voltage input terminal and which transfers an electric current flowing in the transistor, wherein the output changing circuit performs linear variation on the output voltage with a negative coefficient according to a voltage input in the first external terminal.

11. The semiconductor apparatus for power supply control according to claim 10 , further comprising:
a reference voltage source which generates the reference voltage;
a bias circuit which generates an operation electric current supplied to the reference voltage source and the first error amplifier; and
a second external terminal in which a control signal suppl

Assignees

• Maki Shinichiro
• Takano Yoichi
• Yokoyama Katsuhiro
• Mitsumi Electric Co Ltd

Inventors

• Maki Shinichiro
• Takano Yoichi
• Yokoyama Katsuhiro

Classifications

• G05F1/462 Primary

  as a function of the requirements of the load, e.g. delay, temperature, specific voltage/current characteristic · CPC title

• G05F1/575

  characterised by the feedback circuit · CPC title

• G05F1/59 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title

• G05F3/26

  Current mirrors · CPC title

• H02P7/285

  controlling armature supply only · CPC title