CLASS-D AUDIO AMPLIFIER WITH HALF-SWING PULSE-WIDTH-MODULATION

摘要

A class-D audio amplifier with half-swing PWM(Pulse Width Modulation) is provided to reduce effective PWM switching speed to a half and therefore the power loss due to switching loss. A class-D audio amplifier(100) with half-swing PWM(Pulse Width Modulation) includes first and second comparators(116a,116b), and an output switch. The first and second comparators compares a pair of differential signals with half-swing modulation signals respectively to generate first and second PWM signals. The voltage swing of the half-swing modulation signal is smaller than that of the differential signal. The output switch has a pair of inputs which receive the first and second PWM signals, and outputs ternary encoding output signals in response to the first and second PWM control signals.