LINEAR POWER SUPPLY CIRCUIT
First Claim
1. A linear power supply circuit, comprising:
- an output transistor installed between an input terminal to which an input voltage is applied and an output terminal to which an output voltage is applied;
a driver configured to drive the output transistor based on a difference between a voltage that is based on the output voltage and a reference voltage; and
a phase compensation circuit,wherein the driver includes a differential amplifier configured to output a voltage corresponding to the difference between the voltage based on the output voltage and the reference voltage, a first capacitance having one end to which an output of the differential amplifier is applied and the other end to which a ground potential is applied, a converter configured to convert the voltage that is based on the output of the differential amplifier into a current and output the current, and a current amplifier configured to amplify the current output from the converter,wherein a power supply voltage of the differential amplifier and the converter depends on the output voltage, andwherein the phase compensation circuit is configured to lower a gain of a transfer function of the linear power supply circuit and an output capacitor connected to the output terminal by shifting a pole of the transfer function, without the output capacitor affecting the pole, to a low frequency.
1 Assignment
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Accused Products
Abstract
A linear power supply circuit, includes: output transistor between input terminal where input voltage is applied and output terminal where output voltage is applied; a driver driving the output transistor based on difference between voltage based on the output voltage and reference voltage; and phase compensation circuit, wherein the driver includes differential amplifier outputting voltage corresponding to the difference between the voltage based on the output voltage and the reference voltage, a first capacitance having one end where output of the differential amplifier is applied and the other end where ground potential is applied, a converter converting the voltage based on the output of the differential amplifier into current, and a current amplifier amplifying the current output from the converter, and wherein the phase compensation circuit lowers gain of transfer function of the linear power supply circuit and output capacitor connected to the output terminal.
4 Citations
11 Claims
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1. A linear power supply circuit, comprising:
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an output transistor installed between an input terminal to which an input voltage is applied and an output terminal to which an output voltage is applied; a driver configured to drive the output transistor based on a difference between a voltage that is based on the output voltage and a reference voltage; and a phase compensation circuit, wherein the driver includes a differential amplifier configured to output a voltage corresponding to the difference between the voltage based on the output voltage and the reference voltage, a first capacitance having one end to which an output of the differential amplifier is applied and the other end to which a ground potential is applied, a converter configured to convert the voltage that is based on the output of the differential amplifier into a current and output the current, and a current amplifier configured to amplify the current output from the converter, wherein a power supply voltage of the differential amplifier and the converter depends on the output voltage, and wherein the phase compensation circuit is configured to lower a gain of a transfer function of the linear power supply circuit and an output capacitor connected to the output terminal by shifting a pole of the transfer function, without the output capacitor affecting the pole, to a low frequency. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11)
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2. A linear power supply circuit, comprising:
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an output transistor installed between an input terminal to which an input voltage is applied and an output terminal to which an output voltage is applied; a driver configured to drive the output transistor based on a difference between a voltage based on the output voltage and a reference voltage; and a phase compensation circuit, wherein the driver includes a differential amplifier configured to output a voltage corresponding to the difference between the voltage based on the output voltage and the reference voltage, a first capacitance having one end to which an output of the differential amplifier is applied and the other end to which the voltage that is based on the output voltage is applied to, a converter configured to convert the voltage that is based on the output of the differential amplifier into a current and output the current, and a current amplifier configured to amplify the current output from the converter, and a phase compensation circuit, wherein a power supply voltage of the differential amplifier is a first constant voltage and a power supply voltage of the current amplifier is a second constant voltage, or the power supply voltage of the differential amplifier and the power supply voltage of the current amplifier are the input voltage, and wherein the phase compensation circuit is configured to lower a gain of a transfer function of the linear power supply circuit and an output capacitor connected to the output terminal by shifting a pole of the transfer function, without the output capacitor affecting the pole, to a low frequency.
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Specification