Common-mode feedback circuit and differential operational amplifier circuit having stable operation and low power consumption

摘要

A common-mode feedback circuit outputs a control voltage to define a common-mode operating point of a fully differential amplifier. The common-mode feedback circuit has a voltage dividing circuit and a differential amplifier. The voltage dividing circuit divides a voltage across two output ends of the fully differential amplifier. The differential amplifier receives an output voltage of the voltage dividing circuit and a reference voltage, and an output voltage of the differential amplifier is supplied as the control voltage to the fully differential amplifier.