USB self-powered sound card

part:

1x PCM2706 - 32-pin TQFP

1x 12 MHz crystal

1 x 1 megohm resistor

4 x 3.3 kΩ resistors

2 x 1.5 kΩ resistors

2 x 22 ohm resistors

2 x 15 ohm resistors

2 x 100 microfarad capacitors

2 x 47µF capacitors

4 x 1 microfarad capacitors

2 x 22 nanofarad capacitors

2 x 27 picofarad capacitors

Technical Specifications:

Power supply voltage: 5V

Interfaces: USB 1.1, USB 2.0

Output interfaces: Headphone, S/PDIF

Sampling rates: 32 kHz, 44 kHz, 48 kHz

Signal-to-noise ratio: 98dB

Total harmonic distortion: 0.006%

Headphone output power: 12 milliwatts

Power consumption: 35 - 45 mA

Operating systems: Windows 98, ME, 2000, XP, Mac OSX

About the PCM2706 USB sound card/USB headset

This is a high-fidelity external USB sound card/USB headphone project that can be built for your PC or Mac. It's based on the latest PCM2706 integrated circuit, functioning as a high-quality, clear 16-bit stereo DAC. It's a single-chip digital-to-analog converter providing two D/A output stereo channels, a digital S/PDIF output, and requires very few external components. The PCM2706 includes an integrated USB 1.0 and USB 2.0 compatible interface controller and can be conveniently powered directly from a USB connection. The PCM2706 is a USB plug-and-play device and requires no driver installation under Windows XP and Mac OSX.

The PCM2706 chip also offers seven functions controlled via haptic switches. These include volume (increase/decrease), play, stop, previous track, and next track controls. These functions require no software or driver installation and are operational immediately after the PCM2706 is connected to the computer's USB port.

This project includes a PDF of the double-sided 65 mm x 43 mm PCB layout, which you can use to transfer it onto your printed circuit board. Once you have your PCB ready, soldering the PCM2706 chip isn't as difficult as it seems.

PCM2706 block diagram

Printed circuit board

Download PCB layout

(PDF format)

PCB component placement