Patent ID: 8547077
Filing Date: 2013-10-01
Classification: G05F

Abstract:
1. A voltage regulator with adaptive Miller compensation, comprising; a first amplifier coupled to receive a reference voltage and a feedback voltage; a second amplifier coupled to receive an output of the first amplifier; an adaptive compensation circuit with two ends that are coupled to an input node and an output node of the second amplifier respectively, the adaptive compensation circuit comprising a compensation capacitor and a compensation transistor that are serially connected; a bias circuit configured to generate a proper bias control voltage to dynamically control the adaptive compensation circuit in a manner that the adaptive compensation transistor operates in a deep triode region with weakly-inverted channel or strongly-inverted channel; and an output circuit coupled to receive the output of the second amplifier, the output circuit being configured to generate an output voltage of the voltage regulator according to which the feedback voltage is generated; wherein a resistance of the compensation transistor varies according to a load of the voltage regulator under control of the bias control voltage; and wherein the bias circuit generates a mirror current that copies at least a portion of a current flowing in the output circuit, and the bias control voltage is then generated according to the mirror current.