COMPENSATOR CIRCUITRY AND METHOD FOR AN OXYGEN SENSOR

Compensator circuitry (200) is provided for an oxygen sensor (1) which includes a pump cell (5) and a reference cell (4). The compensator circuitry (200) includes a feedback control loop which maintains the reference cell (4) at a reference voltage. The feedback control loop includes a digital compensator (43) which determines and outputs a compensation current to the pump cell (5) dependent on a reference voltage measured from the reference cell (4). The digital compensator (43) also suspends the determination and output of the compensation current for a set time which is dependent on detection of edges in an oxygen sensor heater Pulse Width Modulation signal.