Patent ID: 7227413

Claim:
An audio amplification device comprising: an input for receiving an input audio signal and an output for delivering an output audio signal; an amplifier including a differential pair of MOS transistors, with a first and a second MOS transistor each having a gate, a source, a drain and a bulk; wherein: the gate of the first MOS transistor is coupled to the input of the device; the gate of the second MOS transistor receives a reference voltage which takes the form of a rising ramp when the amplifier is powered up; the drain of either one of the first and second MOS transistors is coupled to the output of the device; and the amplifier additionally includes biasing circuitry for biasing the bulk of the first and second MOS transistors to a first voltage level approximately equal to a supply voltage of the amplifier at the beginning of the reference voltage ramp, and to a second voltage level approximately equal to the voltage of their source at the end of the ramp.