Output driver comprising MOS switches with adjustable back biasing

The present disclosure relates to an integrated circuit output driver, e.g. operating in class-D, for driving an audio transducer. The integrated circuit output driver comprises a first half-bridge driver comprising a first PMOS transistor and a first NMOS transistor connected in series between positive and negative supply voltage rails. A first body terminal is connected to a body of the first PMOS transistor for receipt of a first back bias voltage and a second body terminal connected to a body of the first NMOS transistor for receipt of a second back bias voltage. The integrated circuit output driver comprises a bias voltage generator configured to adjust at least one of the first back bias voltage and the second back bias voltage to control on-resistance of the first PMOS transistor and/or the first NMOS transistor. The integrated circuit output driver is well-suited for hearing aids, headsets and other audio devices.