This PLL is designed for audio clock generation. The reference clock is either 12MHz crystal or the input clock. It supports 256*fs clock output, where fs is the audio system sample rate of 32kHz/44.1kHz/48kHz. It integrates a phase frequency detector (PFD), a loop filter (LP), a voltage control oscillator (VCO), a current reference, two programmable dividers and other supportive circuits.