Patent ID: 7619467
Filing Date: 2009-11-17
Classification: H03F

Abstract:
1. An amplifier circuit, comprising: a rectifier for receiving an AC signal and for generating a rectified DC signal; a voltage divider circuit for receiving the rectified DC signal and for generating a unity voltage signal; a first multiplier circuit having a first and a second input terminal to which are applied the unity voltage signal, the first multiplier circuit generating a first multiplied signal; a second multiplier circuit having a first and a second input terminal to which are applied the first multiplied signal and a triangular wave signal, respectively, the second multiplier circuit generating a modulated triangular wave signal; a comparator circuit having a first and a second input terminal to which are applied the modulated triangular wave signal and an audio signal, respectively, the comparator circuit generating a pulse width modulated gating signal; and a transistor having a gate terminal to which is applied the pulse with modulated gating signal, the transistor generating an amplified signal responsive to the pulse width modulated gating signal.