Constant-voltage power circuit
First Claim
1. A constant-voltage power circuit comprising:
- a control voltage output circuit receiving a reference voltage and a divided voltage dividing an output voltage, and outputting a control voltage in accordance with the difference between the reference voltage and the divided voltage;
an output circuit receiving the control voltage to generate a stabilized output voltage from a high-potential-side power supply voltage, wherein the output circuit includes an output node to output the stabilized output voltage;
a first P-type MOS transistor carrying a current from the output node;
a capacitor connected between the output node and a supply node of low-potential-side power supply voltage; and
a P-type MOS transistor current control circuit controlling a gate of the first P-type MOS transistor so that a current flowing through the first P-type MOS transistor becomes a constant value,wherein the P-type MOS transistor current control circuit includes;
a constant-current source having a first terminal and a second terminal, the first terminal being connected to the supply node of low-potential-side power supply voltage; and
at least one second P-type MOS transistor having gate and drain mutually connected, and a current path between source and drain, which is interposed between a supply node of the high-potential-side power supply voltage and the second terminal of the constant-current source,wherein the gate of the first P-type MOS transistor is connected to the other terminal of the constant-current source.
1 Assignment
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Accused Products
Abstract
A differential amplifier receives a reference voltage and a divided voltage dividing an output voltage, and outputs a control voltage in accordance with the difference between the reference voltage and the divided voltage. The control voltage output from the differential amplifier is supplied to an output amplifier. The output amplifier generates a stabilized output voltage from a high-potential-side power supply voltage in accordance with the control voltage. A P-type MOS transistor is connected to a node of the output voltage, and the MOS transistor carries a current from the node of the output voltage. A current control circuit controls a gate of the P-type MOS transistor so that the current flowing through the P-type MOS transistor becomes a constant value.
10 Citations
18 Claims
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1. A constant-voltage power circuit comprising:
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a control voltage output circuit receiving a reference voltage and a divided voltage dividing an output voltage, and outputting a control voltage in accordance with the difference between the reference voltage and the divided voltage; an output circuit receiving the control voltage to generate a stabilized output voltage from a high-potential-side power supply voltage, wherein the output circuit includes an output node to output the stabilized output voltage; a first P-type MOS transistor carrying a current from the output node; a capacitor connected between the output node and a supply node of low-potential-side power supply voltage; and a P-type MOS transistor current control circuit controlling a gate of the first P-type MOS transistor so that a current flowing through the first P-type MOS transistor becomes a constant value, wherein the P-type MOS transistor current control circuit includes; a constant-current source having a first terminal and a second terminal, the first terminal being connected to the supply node of low-potential-side power supply voltage; and at least one second P-type MOS transistor having gate and drain mutually connected, and a current path between source and drain, which is interposed between a supply node of the high-potential-side power supply voltage and the second terminal of the constant-current source, wherein the gate of the first P-type MOS transistor is connected to the other terminal of the constant-current source. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A constant-voltage power circuit comprising:
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a control voltage output circuit receiving a reference voltage and a divided voltage dividing an output voltage, and outputting a control voltage in accordance with the difference between the reference voltage and the divided voltage; an output circuit receiving the control voltage to generate a stabilized output voltage from a high-potential-side power supply voltage, wherein the output circuit includes an output node to output the stabilized output voltage; a first N-type MOS transistor carrying a current into the output node; a capacitor connected between the output node and a supply node of low-potential-side power supply voltage; and an N-type MOS transistor current control circuit controlling a gate of the first N-type MOS transistor so that a current flowing through the first N-type MOS transistor becomes a constant value, wherein the N-type MOS transistor current control circuit includes; a constant-current source having a first terminal and a second terminal, the first terminal is connected to the supply node of high-potential-side power supply voltage; and at least one second N-type MOS transistor having gate and drain mutually connected, and a current path between source and drain, which is interposed between a supply node of the low-potential-side power supply voltage and the second terminal of the constant-current source, wherein the gate of the first N-type MOS transistor is connected to the second terminal of the constant-current source. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A constant-voltage power circuit comprising:
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a control voltage output circuit receiving a reference voltage and a divided voltage dividing an output voltage, and outputting a control voltage in accordance with the difference between the reference voltage and the divided voltage; an output circuit receiving the control voltage to generate a stabilized output voltage from a high-potential-side power supply voltage, wherein the output circuit includes an output node to output the stabilized output voltage; a first P-type MOS transistor carrying a current from the output node; a first N-type MOS transistor carrying a current into the output node; a capacitor connected between the output node and a supply node of low-potential-side power supply voltage; a P-type MOS transistor current control circuit controlling a gate of the first P-type MOS transistor so that a current flowing through the first P-type MOS transistor becomes a constant value; and an N-type MOS transistor current control circuit controlling a gate of the first N-type MOS transistor so that a current flowing through the first N-type MOS transistor becomes a constant value. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification