Voltage regulator having error amplifier

摘要

According to an embodiment, a voltage regulator having an output transistor, a voltage dividing circuit, an error amplifier, a detection circuit and a phase compensation capacitance circuit is provided. The output transistor has one end to which a power supply voltage is supplied, a control terminal to which a control signal is input, and the other end which outputs an output voltage. The voltage dividing circuit is connected between the other end of the output transistor and a first reference voltage. The error amplifier is configured to output the control signal according to the difference between a divided voltage and a second reference voltage. The detection circuit is configured to detect an operation environment. The phase compensation capacitance circuit is configured to adjust a phase compensation capacitance between the other end of the output transistor and an input terminal of the error amplifier, in accordance with the detected operation environment.

主权项

1. A voltage regulator, comprising:
an output transistor having a first end to which a power supply voltage is supplied, a control terminal to which a control signal is input, and a second end which outputs an output voltage; a voltage dividing circuit which is connected between the second end of the output transistor and a first reference voltage, the voltage dividing circuit being configured to output a divided voltage according to the output voltage; an error amplifier which has a first input terminal to which the divided voltage is provided, and a second input terminal to which a second reference voltage is provided, the error amplifier being configured to output the control signal according to a difference between the divided voltage and the second reference voltage; a detection circuit configured to detect an operation environment; and a phase compensation capacitance circuit configured to adjust a phase compensation capacitance between the second end of the output transistor and the first input terminal of the error amplifier in accordance with the operation environment, wherein the detection circuit is configured to detect a temperature as the operation environment, the phase compensation capacitance has a temperature dependency, and the phase compensation capacitance circuit is configured to adjust the phase compensation capacitance so as to approach a predetermined reference capacitance in accordance with the detected temperature.