Patent ID: 8022757
Filing Date: 2011-09-20
Classification: H03F

Abstract:
1. A class D power amplifier comprising: a signal input terminal for receiving an analog input signal; an analog signal processing unit, connected to said signal input terminal, for processing said analog signal; an integrating circuit for integrating the analog signal output from said analog signal processing unit; a PWM circuit for providing pulse width modulation (PWM) to an integration signal output from said integrating circuit, so as to generate a PWM signal; and a signal output terminal via which the pulse width modulation signal generated by said PWM circuit is output, said analog signal processing unit including: a first amplifier, connected to said signal input terminal, for amplifying said analog input signal; a second amplifier for outputting a direct current voltage as an output signal; a signal switching circuit, which has first and second terminals for receiving the output signals of said first amplifier and said second amplifier respectively and to which a switching control signal having a predetermined time is applied; and a third amplifier having an input terminal and an output terminal respectively connected to an output terminal of said signal switching circuit and said integrating circuit, the output signal of one of said first amplifier and said second amplifier being sent to said output terminal of said third amplifier in accordance with said switching control signal.