Patent ID: 9431978
Filing Date: 2016-08-30
CPC Classification: H03F

Claim Text:
1. A common-mode feedback differential amplifier circuit, comprising: a common-mode feedback (CMFB) loop; and a differential amplifier, wherein the CMFB loop is configured to perform voltage division on a first common-mode signal to generate a second common-mode signal and a third common-mode signal, output the second common-mode signal and the third common-mode signal to the differential amplifier, and control, according to a negative feedback principle, the differential amplifier to output an output signal with a minimum voltage equal to a voltage of the first common-mode signal, and wherein the differential amplifier is configured to receive the second common-mode signal and the third common-mode signal, set a higher one of voltages of the second common-mode signal and the third common-mode signal equal to a voltage of a first input terminal or a second input terminal, and output, under control of the CMFB loop, the output signal with the minimum voltage equal to the voltage of the first common-mode signal.