Patent ID: 7586370
Filing Date: 2009-09-08
Classification: H03F

Abstract:
1. A class D amplifier comprising: a first PWM circuit for receiving input data and converting the input data to a first PWM signal; a power amplifier for amplifying the first PWM signal; a low pass filter for passing low frequency components of the amplified first PWM signal to a load; a second PWM circuit for converting the input data to a second PWM signal; a first filter for only passing wanted frequency components of the second PWM signal; a second filter for only passing wanted frequency components of the amplified first PWM signal from the power amplifier; a difference detector for detecting a difference between a first filter output signal output from the first filter and a second filter output signal output from the second filter; a conversion unit for converting the detected signal difference to digital data; and a feedback unit for feeding back the converted digital data to an input of the first PWM circuit.