Transconductance amplifier having common mode feedback circuit and method of operating the transconductance amplifier

A transconductance amplifier, comprising:

• a first-type transconductor for generating a first differential output signal pair in response to a differential input signal pair under control of a first control signal;
• a second-type transconductor for generating a second differential output signal pair in response to the differential input signal pair under control of a second control signal;
• and
• a common mode feedback circuit for generating the second control signal in response to the first and second differential output signal pairs under control of a common mode control signal, wherein the common mode feedback circuit generates a comparison output signal by comparing the first and second differential output signal pairs with the common mode control signal, and limits a variation range of the comparison output signal to generate the second control signal.