Patent ID: 6304137
Filing Date: 2001-10-16
Classification: H02M,H03F

Abstract:
A class D amplifier with reduced electromagnetic interference comprising:upper and lower power supply buses;a pulse width modulator coupled between the supply busses for receiving an input audio signal and for generating a pulse width modulated output signal where the width of a pulse is proportional to the amplitude of the audio input;an output bridge with upper and lower mosfets, wherein the output of the pulse width modulator is coupled to the gates of the bridge mosfets;first and second inductors, each coupled to an output terminal of the amplifier and the first inductor coupled to the upper mosfet and the second inductor coupled to the lower mosfet;first and second commutating diodes, the first commutating diode coupled to first inductor and to the lower bus and the second commutating diode coupled to the second inductor and to the upper bus;a first diode and bead network coupled in series with the upper mosfet and the upper bus; anda second diode and bead network coupled in series with the lower mosfet and the lower bus.