WM8740: High performance stereo DAC


The WM8740 is a very high performance stereo DAC designed for audio applications such as CD, DVD, home theatre systems, set top boxes and digital TV. The WM8740 supports data input word lengths from 16 to 24-bits and sampling rates up to 192kHz. The WM8740 consists of a serial interface port, digital interpolation filter, multi-bit sigma delta modulator and stereo DAC in a small 28-pin SSOP package. The WM8740 also includes a digitally controllable mute and attenuator function on each channel.

The internal digital filter has two selectable roll-off characteristics. A sharp or slow roll-off can be selected dependent on application requirements. Additionally, the internal digital filter can be by-passed and the WM8740 used with an external digital filter.

The WM8740 supports two connection schemes for audio DAC control. The SPI-compatible serial control port provides access to a wide range of features including on-chip mute, attenuation and phase reversal. A hardware controllable interface is also available.


  • 120dB SNR (’A’ weighted, mono @ 48kHz)
  • 117dB SNR (’A’ weighted, stereo @ 48kHz)
  • 104dB THD (’A’ weighted @ 48kHz)
  • Sampling frequency : 8kHz - 192kHz
  • Input data word : 16 to 24-bit
  • Selectable digital low pass filter
  • Optional interface to industry standard external filters
  • Hardware or 3-wire SPI control
  • Fully dfferential voltage outputs