METHOD AND APPARATUS OF AN ACOUSTIC ENERGY DETECTION CIRCUIT FOR A PULSE DENSITY MODULATION MICROPHONE

摘要

A pulse density modulation (PDM) signal energy detection circuit includes a digital to analog converter circuit for receiving a PDM digital input signal and generating an analog output signal based on the PDM digital input signal. The PDM signal energy detection circuit further includes a comparator circuit for receiving the analog output signal from the digital-to-analog converter circuit and generating a pulse signal when the magnitude of the analog output signal exceeds a preset threshold. The PDM signal energy detection circuit further includes a counter circuit for receiving the pulse signal from the comparator circuit and generating an energy detection signal when the number of consecutive pulse signals exceeds a preset number of times.