Audio amplification device for mobile phone, has biasing circuit which biases bulk of MOS transistors with voltages equal to supply voltage and voltage of node at beginning and end of ramp of reference voltage, respectively

摘要

The device has an amplifier (A01) comprising a differential pair of metal oxide semiconductor (MOS) transistors (MP1, MP2). The amplifier has a biasing circuit (40) to bias a bulk of the transistors with a voltage equal to supply voltage (Vdd) of the amplifier at the beginning of ramp of a reference voltage (VREF) and with another voltage equal to voltage of a node (BB) at the end of the ramp. An independent claim is also included for a method of charging an amplifier in an audio amplification device.