An integrated circuit includes a transconductance circuit having a bias current generator coupled to a power supply. The bias current generator may include a current mirror circuit having an input and an output, where a current at the output is proportional to a current at the input. A first constant current source in the transconductance circuit has a first electrode coupled to the power supply. The transconductance circuit also includes first and second transistors and a diode. The diode is forward biased by the bias current generator. The first transistor has a collector coupled to a second electrode of the first constant current source and to a signal output. The second transistor has a drain coupled to an emitter of the first transistor, a source coupled to a reference voltage and a gate coupled to a signal input. The diode has an anode coupled to a base of the first transistor and a cathode coupled to a constant voltage source. The current through the diode results in a drain-source voltage of the second transistor being constant. As a result, the transconductance circuit operation is linearized, and distortion due to drain-source voltage variation in the second transistor is reduced.