The DS4201 Universal Serial Bus (USB) audio device is a complete interface solution for USB based PC digital audio playback. Integrating a USB device core, stereo 16bit sigmadelta DAC and fixed function DSP processing, as shown in Figure 1, the DS4201 is designed specifically for USB digital speaker implementations. Digitaltoanalog audio data processing supports 8 and 16bit PCM stereo/mono formats at 44.1 KHz and 48.0 KHz sampling rates. Additionally, analog output mixing of line and microphone inputs provide legacy and hybrid speaker capabilities.