Method and device for eliminating noise in class-D power amplifier

Abstract

The invention relates to a method and a device for eliminating noise in a class-D power amplifier. The class-D power amplifier comprises an integrator, a triangular wave generator, comparators, a driving stage, an output stage and a feedback network. In the invention, the triangular wave generator is adopted to generate a triangular wave, and an adjustable delay circuit is adopted to delay the triangular wave and respectively input the delayed triangular wave and the original triangular wave to the input ends of the two comparators; or two independent triangular wave generators are adopted to generate two independent triangular waves, the adjustable delay circuit is arranged behind one of the triangular wave generators so as to generate a delayed triangular wave, and the delayed triangular wave and the triangular wave generated by the other triangular wave generator are applied to the input ends of the two comparators together, thus the two output ends of the class-D power amplifier generate delays, so that certain effective signals are held on a load when output pulse signals are switched. The invention can effectively restrain or eliminate the noise generated at the output ends of the class-D power amplifier, and ensure the class-D power amplifier to maintain smaller quiescent current.

Description

technical field [0001] The invention particularly relates to a method and device for eliminating noise and reducing quiescent current in a class D power amplifier. Background technique [0002] Most of the commonly used Class D power amplifiers currently use a fully differential non-inverting structure, that is, including an integrator, a comparator, a driver stage, an output stage, a triangle wave generator, and a feedback network. Integrators are usually implemented with differential operational amplifiers and capacitors. The input analog signal and output pulse feedback signal are input to the input terminal of the integrator at the same time, and the integrator outputs two sawtooth wave signals with opposite phases that vary with the input signal. These two signals It is added to the input terminals of the two comparators, and compared with the triangular wave generated by the triangular wave generator, the pulse signal is output; the pulse signal is sent to the output s...

AI Technical Summary

Problems solved by technology

When the vast majority of this class D power amplifier has no input signal, the two output terminals are in the same phase, which can reduce the quiescent current, but when the output pulse is switched, because two switch tubes at one output terminal are turned on or off at the same time , the effective signal on the load is zero, and the noise is easily reflected at the output, which will bring noise to the load

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