A method for using driver circuitry to drive a load having an unknown impedance magnitude includes (a) in a configuration mode of the driver circuitry, determining a required power supply voltage for a driver stage to drive the load, and (b) in a driving mode of the driver circuitry, (1) driving the load via the driver stage in response to an input signal, and (2) controlling a power supply to provide the required power supply voltage to the driver stage as a static voltage, while driving the load via the driver stage in response to the input signal.