Patent ID: 8310313

Claim:
A highly efficient class-G amplifier comprising: an amplifier circuit coupled between a positive power rail and a negative power rail for amplifying an audio input signal; a boost inverting power converter coupled to the positive and negative power rails for converting a supply voltage to a positive rail voltage and a negative rail voltage on the positive and negative power rails respectively; and an audio level detector coupled to the boost inverting power converter for detecting the audio input signal for the boost inverting power converter to adjust the positive and negative rail voltages; the boost inverting power converter comprising: a boost inverting power stage coupled to the positive and negative power rails and a power input terminal receiving the supply voltage; and a controller coupled to the boost inverting power stage for switching the boost inverting power stage between a boost mode and an inverting mode; the boost inverting power stage comprising: an inductor; a first power switch coupled between the power input terminal and inductor; a second power switch coupled between the inductor and a ground terminal; a first diode coupled between the negative power rail and inductor; a second diode coupled between the inductor and positive power rail; a first capacitor coupled to the negative power rail; a second capacitor coupled to the positive power rail; a first voltage divider coupled to the negative power rail for dividing the negative rail voltage to generate a first feedback signal for the controller; and a second voltage divider coupled to the positive power rail for dividing the positive rail voltage to generate a second feedback signal for the controller.