Patent ID: 8129966
Filing Date: 2012-03-06
Classification: G05F

Abstract:
1. A voltage regulator circuit comprising: an input terminal; an output terminal; an output transistor configured to pass a current from the input terminal to the output terminal in accordance with a control signal; a reference voltage generator unit configured to generate and output a reference voltage; an output voltage detector unit configured to detect an output voltage output from the output terminal and generate and output a proportional voltage proportional to a detected output voltage; a first error amplifier unit configured to control the output transistor to make the proportional voltage equal to the reference voltage; and a second error amplifier unit configured to respond to fluctuation in the output voltage faster than the first error amplifier unit and increase the output current output from the output transistor for a period of time when the output voltage rapidly drops, wherein the second error amplifier comprises a first constant current source supplying a first constant current and a second constant current source supplying a second constant current, and a bias current of the second error amplifier unit is changed in accordance with the current output from the output transistor.