VOLTAGE REGULATOR

摘要

Provided is a voltage regulator having satisfactory transient response characteristics. The voltage regulator includes: a first amplifier for detecting that undershoot occurs in an output voltage; a second amplifier for detecting that overshoot occurs in the output voltage; a first constant current circuit for increasing a bias current of an error amplifier circuit by a first amount for a first time period in response to a signal determined based on one of an output signal of the first amplifier and an output signal of the second amplifier; a second constant current circuit for increasing the bias current of the error amplifier circuit by a second amount larger than the first amount for a second time period shorter than the first time period in response to a signal determined based on the output signal of the first amplifier; and a first switch circuit for pulling up a gate of an output transistor in response to a signal determined based on the output signal of the second amplifier.

主权项

1. A voltage regulator, comprising:
an error amplifier circuit for amplifying a difference between a divided voltage obtained by dividing an output voltage output from an output transistor and a reference voltage, and for outputting the amplified difference to control a gate of the output transistor; a first amplifier for detecting that undershoot occurs in the output voltage; a second amplifier for detecting that overshoot occurs in the output voltage; a first constant current circuit for increasing a bias current of the error amplifier circuit by a first amount for a first time period in response to a signal determined based on one of an output signal of the first amplifier and an output signal of the second amplifier; a second constant current circuit for increasing the bias current of the error amplifier circuit by a second amount larger than the first amount for a second time period shorter than the first time period in response to a signal determined based on the output signal of the first amplifier; and a first switch circuit for pulling up the gate of the output transistor in response to a signal determined based on the output signal of the second amplifier.