#$%^&*AU2012200931B220140508.pdf#####SWITCHED RESONANT ULTRASONIC POWER AMBLIFIER SYSTEM ABSTRACT A system for controlling an output of an ultrasonic device (200) is disclosed. The 5 system comprises: an amplifier (100) receiving and processing a driver (190) output signal for generating a drive signal that is provided to an ultrasonic device for controlling output thereof； an output control circuit configured to receive and process a signal related to a feedback signal generated by the ultrasonic device and a divider reference signal configured to generate a compensated clock signal that is adjusted for at least one of io phase and frequency differences between the received feedback signal and the divider reference signal； and a compensated drive circuit (157). The compensated drive circuit (157) includes divider circuitry configured to step down the frequency of the compensated clock signal to a selectable frequency for generating a counter output signal； flip-flop circuitry adapted to split the counter output signal into first and second is complementary square waves together forming a driver input signal, wherein a sample of at least one of the first and second complementary square waves is the divider reference signal； and a driver adapted to amplify the drive signal to generate the driver output signal. The driver includes a phase delay circuit configured to selectively adjust at least one of the driver output signal and pulse width of the pulses of at least one of the first and 20 second complementary signals of the driver output signal
