Circuitry for driving a load, the circuitry comprising: driver circuitry; load sensing circuitry; and a parameter estimation engine, wherein the circuitry is operable in: a driving mode of operation in which the driver circuitry supplies a drive signal to a load coupled to the circuitry; and a load sensing mode of operation, for estimating a characteristic of a load coupled to the circuitry based on a signal output by the load sensing circuitry in response to a stimulus signal supplied to the driver circuitry, and wherein the circuitry is operable to perform a calibration operation in which the parameter estimation engine generates a circuit parameter for use in the load sensing mode based, at least in part, on a signal generated by the circuitry in response to a calibration stimulus signal supplied to the driver circuitry.