WM8775: Stereo ADC with 4 input selector


The WM8775 is a high performance, stereo audio ADC with a 4 channel input mixer. The WM8775 is ideal for digitising multiple analogue sources for surround sound processing applications for home hi-fi, automotive and other audio visual equipment.

A stereo 24-bit multi-bit sigma delta ADC is used with a four stereo channel input selector. Each channel has programmable gain control. Digital audio output word lengths from 16-32 bits and sampling rates from 32kHz to 96kHz are supported.

The audio data interface supports I2S, left justified, right justified and DSP digital audio formats.

The device is controlled via a 2 or 3 wire serial interface. The interface provides access to all features including channel selection, volume controls, mutes, de-emphasis and power management facilities.

The device is available in a 28-pin SSOP package. The WM8775 is software compatible with the WM8776.


  • Audio Performance
  • 102dB SNR (’A’ weighted at 48kHz)
  • -90dB THD
  • ADC Sampling Frequency: 32kHz - 96kHz
  • Four stereo ADC inputs with analogue gain adjust from +24dB to -21dB in 0.5dB steps
  • Digital gain adjust from -21.5dB to -103dB.
  • Programmable Automatic Level Control (ALC) or Limiter on ADC input
  • 3-Wire SPI Compatible or 2-wire Serial Control Interface
  • Master or Slave Clocking Mode 
  • Programmable Audio Data Interface Modes
  • I2S, Left, Right Justified or DSP
  • 16/20/24/32 bit Word Lengths
  • 2.7V to 5.5V Analogue, 2.7V to 3.6V Digital Supply Operation