A high-transconductance high-linearity CMFB circuit

In order to improve the linearity of the traditional differential-difference-amplifier common-mode feedback (CMFB) in dealing with the large amplitude differential output voltage, the source degeneration resistor is used. An innovative current-recycling method is proposed, with which the area and power consumption are constant while increasing the transconductance of the CMFB, thereby compensating for the reduction of the CMFB loop gain and GBW. In combination with high-speed current mirror technology, high enhancements can be achieved while maintaining sufficient phase margin.