Texas Instruments PCM270xC single-chip USB stereo audio digital-to-analog converters (DACs) feature a USB-compliant full-speed protocol controller and S/PDIF. The USB-protocol controller on these TI USB audio DACs works with no software code, but USB descriptors can be modified in some areas (for example, vendor ID/product ID) through the use of an external ROM (PCM2704C) or SPI™ (PCM2705C). TI PCM270xC USB audio DACs also employ SpAct™ architecture, a TI system that recovers the audio clock from USB packet data. On-chip analog phase-locked loops (PLLs) with SpAct enable playback with low clock jitter. These TI audio DACs are ideal for use in USB headphones, audio speakers, CRT/LCD monitors, and audio interface boxes.