Codec with Headphone Driver

The WM8731 is a low power stereo codec with an integrated headphone driver. Stereo line and mono microphone level audio inputs are provided, along with a mute function, programmable line level volume control and a bias voltage output suitable for an electric type microphone. Digital audio input word lengths from 16-32 bits and sampling rates from 8 kHz to 96 kHz are supported. Stereo audio outputs are buffered for driving headphones from a programmable volume control, line level outputs are also provided along with anti-thump mute and power up/down circuitry. The device is controlled via a 2 or 3 wire serial interface. The interface provides access to all features including volume controls, mutes, de-emphasis and extensive power management facilities.


  • Stereo audio codec with integrated headphone driver (50mW on 16W @ 3.3V)
  • 1.42 – 3.6 V digital supply
  • 2.7 – 3.6 V analog supply (standard)
  • 1.8 – 3.6 V analog supply (’L’ version)
  • Playback mode power consumption < 18mW
  • 100 dB SNR (‘A’ weighted @ 48kHz) DAC
  • 90 dB SNR (‘A’ weighted @ 48kHz) ADC
  • Sampling frequency: 8 – 96 kHz
  • Master or slave clocking mode
  • USB clocking mode can generate all common MP3 sample rates (incl. 441.kHz) directly from USB clock
  • Output volume and mute controls
  • Microphone input and electret bias with side tone mixer
  • Selectable ADC high pass filter
  • 2 or three-wire MPU serial control interface
  • Programmable audio data interface modes
  • 28-Pin SSOP package

Parametric Specifications

DACs 2
ADCs 2
DAC THD+N (dB) -84
ADC THD+N (dB) -80
Sample Rate (kHz) 96
Package 28 QFN

Technical Documents

WM8731 Product Datasheet

Oct 1, 2012, v4.9 : 779 Kb

6061 EV1 REV1 Schematic and Layout

Jan 1, 2008, v1.1 : 6500 Kb

WM8731L-6061-FL28-M-REV1 Schematic and Layout

Nov 1, 2007, v1.0 : 1400 Kb


Comprehensive Solutions