Patent ID: 7196580

Claim:
A digital audio amplifier comprising: a power PMOS transistor which has a source to which a first power supply voltage is applied and a drain connected to a common node; a power NMOS transistor which has a drain connected to the common node and a source to which a second power supply voltage is applied; an output node filter which is connected to the common node; a phase lead-lag compensator which lead-lag compensates for the phase of an output signal of the output node filter; an error amplifier which compares an output signal of the phase lead-lag compensator with an input audio signal and amplifies an error between the output signal and the input audio signal; a comparator which converts an error amplified by the error amplifier into a pulse signal; and a gate driver which controls a gate of the power PMOS transistor and a gate of the power NMOS transistor in response to the pulse signal, wherein the phase lead-lag compensator increases self-oscillation frequency by lead-lag-compensating for the phase of the output signal of the output node filter.