SYSTEM AND METHOD FOR CONTROLLING COMMON MODE VOLTAGE VIA REPLICA CIRCUIT AND FEEDBACK CONTROL

The disclosure relates to a system and method for controlling a common mode voltage of an output differential signal of a differential signal processing circuit using a replica circuit and feedback control. The differential signal processing circuit includes two load devices, two input transistors, and two current-source transistors coupled in series between voltage rails, respectively. The replica circuit includes replica load device, replica input transistor, and replica current-source transistor coupled in series between the voltage rails. The common mode voltage of the input differential signal is applied to the replica input transistor to generate a replica output common mode voltage. A feedback circuit generates a bias voltage for the replica current-source transistor and the current-source transistors of the differential circuit to set and control the replica output common mode voltage and the output common mode voltage of the differential signal processing circuit to a target common mode voltage.