Abstract: A digitally controlled microphone with audio compressor includes a capsule; a compressor circuitry having a compressor engine, a digitally controlled root mean square (RMS) detector and a digitally controlled analog processor; a bypass switch to the compressor circuitry; an analog to digital converter (ADC); a digital processor that sends digital audio to a host and receives a second digital audio signal; a digital to analog converter (DAC) and a summing circuit that combine the audio with the audio from the host and send it to a digitally-controlled headphone amplifier and a headphone jack; a microphone body; a serial host interface connector; and hardware controls on the microphone body.

Abstract: A phase locked loop circuit may be utilized as a low jitter clock regenerator in order to generate an extremely stable low jitter signal which is to a large extent immune from input phase and frequency noise. The slaving clock generates an output at a fixed phase relationship to a reference input. The clock regenerator is advantageously implemented by a logic gate type phase detector connected to a multi-stage loop filter. The loop filter output is connected to a phase correction circuit whose output is mixed with the loop filter output to provide a control input to a voltage controlled oscillator. The voltage controlled oscillator output may be provided directly, or through a frequency divider, to a feed-back input of the phase detector.