Patent ID: 8054133

Claim:
A device for eliminating feedback common mode signals, comprising an operational amplifier circuit, wherein the operational amplifier circuit comprises two output ends, the two output ends are a first output end and a second output end, the device further comprising: a feedback unit, configured to receive level signals of the first output end and the second output end of the operational amplifier circuit, and superpose feedback common mode signals to input ends of the operational amplifier circuit according to the states of the level signals; wherein the feedback unit is further configured to: (a) superpose low level feedback common mode signals to the input ends of the operational amplifier circuit when both the level signals of the first and second output ends are high level and (b) superpose high level feedback common mode signals to the input ends of the operational amplifier circuit when both the level signals of the first and second output ends are low level; and (c) not superpose the feedback common mode signals to the input ends of the operational amplifier circuit when the level signals of the first and second output ends are of different values.