Question

5. a) What are the pros and cons of a sine wave PWM inverter versus a plain square wave inverter? b) Sketch a block diagram ofa Class D audio amplifier, and briefly explain how it is related to a PwM sine wave inverter and amplifies an input audio signal. c) Suppose we have a single tone audio signal of frequency, 10 KHz, and the carrier frequency is 100 KHz. Sketch the approximate power spectrum of the output waveform. Does the output need to be filtered to improve the quality of the amplified audio and if so, what kind of filter is needed? Also, what if the carrier frequency is increased to 300 KHz? Do we need a low pass filter in this case and if so, is this filter simpler than the previous one or more stringent? e) Compare the pros and cons of a bipolar versus unipolar PWM switching schemes?

Answer 1

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