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US 10,871,793 B2Granted
Constant voltage power source circuit
AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
InventorsToshimasa Namekawa, Kosuke Tashiro
Life of this patent
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Abstract
According to an embodiment, a constant voltage power source circuit has a voltage feedback circuit that controls an output voltage depending on a control voltage. It has a current feedback circuit that detects an output current, keeps the control voltage at a constant voltage until the output current reaches a predetermined current value, and changes a value of the control voltage at a time when the output current reaches the predetermined current value.
Claims14
A constant voltage power source circuit, comprising:
- a voltage feedback circuit that controls an output voltage depending on a control voltage;
- and
- a current feedback circuit that detects an output current, keeps the control voltage at a constant voltage until the output current reaches a predetermined current value, and changes a value of the control voltage at a time when the output current reaches the predetermined current value,
- wherein the voltage feedback circuit includes:
- an amplifier that outputs a signal dependent on a voltage difference between a feedback voltage dependent on the output voltage and the control voltage, and
- a first output transistor that is controlled by an output signal from the amplifier and supplies the output voltage to an output terminal,
- wherein the amplifier has an inverting input terminal and a non-inverting input terminal, the feedback voltage is supplied to the non-inverting input terminal, and the control voltage is supplied to the inverting input terminal,
- wherein the current feedback circuit has a second output transistor that composes a current mirror circuit together with the first output transistor, and
- wherein the voltage feedback circuit further includes a first phase compensation circuit that is connected between an output terminal of the amplifier and the non-inverting input terminal and compensates for a phase delay.
6 more elements
A constant voltage power source circuit, including:
- a reference voltage output circuit that outputs a reference voltage;
- a first amplifier that amplifies a difference voltage between the reference voltage and a feedback voltage dependent on an output current to output an output;
- a first comparator that compares the output of the first amplifier with the reference voltage;
- a first selection circuit that selects and outputs either one of the reference voltage and the output of the first amplifier in response to an output of the first comparator;
- a second amplifier that is supplied with an output of the first selection circuit and a feedback voltage dependent on an output voltage and amplifies a difference voltage therebetween to output a driving voltage;
- and
- a first output transistor that is provided with a control electrode that is supplied with the driving voltage, and supplies the output voltage to an output terminal.
4 more elements
A constant voltage power source circuit, including:
- a reference voltage output circuit that outputs a reference voltage;
- a voltage generation circuit that outputs a voltage provided in such a manner that a voltage that is predetermined times as much as the reference voltage is added to a feedback voltage dependent on an output voltage;
- a first selection circuit that selects and outputs either one of the reference voltage and an output of the voltage generation circuit;
- a first amplifier that amplifies a difference voltage between an output of the first selection circuit and a feedback voltage dependent on an output current to output an output;
- a second selection circuit that selects and outputs either one of the reference voltage and the output of the first amplification circuit;
- a second amplification circuit that is supplied with an output of the second selection circuit and the feedback voltage dependent on the output voltage and amplifies a difference voltage therebetween to output a driving voltage;
- and
- an output transistor that is provided with a control electrode that is supplied with the driving signal, and supplies the output voltage to an output terminal.
5 more elements
Dependencies are inferred from the claim text.