Patent ID: 8704605

Claim:
A resonant element driver circuit comprising: a pair of transistors configured to drive a resonant element, the pair of transistors comprising a first transistor and a second transistor; first biasing circuitry configured to bias the first transistor; and second biasing circuitry configured to bias the second transistor, wherein the second biasing circuitry is configured to receive a reference signal independent of a voltage source, the second biasing circuitry configured to use the reference signal in order to bias the second transistor, wherein the second biasing circuitry comprises: an amplifier configured to receive the reference signal; and a feedback loop in communication with the amplifier, the feedback loop being configured to send a feedback signal indicative of a biasing point of the second transistor to the amplifier, wherein the amplifier is configured to compare the feedback signal with the reference signal and output an output signal that sets the biasing on the second transistor.