PCM1721

The PCM1721 is a complete low cost stereo audiodigital-to-analog converter (DAC) with a phase-lockedloop (PLL) circuit included. The PLL derives either256fS or 384fS system clock from an external 27MHzreference frequency. The DAC contains a 3rd-order ∆modulator, a digital interpolation filter, and an analogoutput amplifier. The PCM1721 can accept 16-, 20-, or24-bit input data in either normal or I2S formats.

The digital filter performs an 8X interpolation func-tion and includes selectable features such as soft mute,digital attenuation and digital de-emphasis. The PLLcan be programmed for sampling at standard digitalaudio frequencies as well as one-half and doublesampling frequencies.

The PCM1721 is ideal for applications which combinecompressed audio and video data such as DVD, DVD-ROM, set-top boxes and MPEG sound cards.