Multi-channel Codec with Three Digital Audio Interfaces

The WM8994 is a highly integrated, ultra low power hi-fi codec with an integrated stereo Class D and AB speaker driver, and a Class W headphone driver to minimize power consumption during audio playback. The device requires only Vbatt and a 1.8V supply, generating all other internal supply rails from integrated LDOs. Stereo full duplex asynchronous sample rate conversion and multi-channel digital mixing combined with powerful analog mixing to support a wide range of different architectures and use cases. A fully programmable parametric EQ provides speaker compensation and a dynamic range controller can be used in the ADC or DAC paths for maintaining a constant signal level, maximizing loudness and protecting speakers against overloading and clipping. A smart digital microphone interface provides power regulation, a low jitter clock output and decimation filters for up to four digital microphones. A MIC activity detect with interrupt is available. Active ground loop noise rejection and DC offset correction help prevent pop noise and suppress ground noise on the headphone outputs.


  • Hi-fi 24-bit 4-channel DAC and 2-channel ADC
  • 100 dB SNR during DAC playback (‘A’ weighted)
  • Smart MIC interface
    • Power, clocking and data input for up to four digital MICs
    • High performance analog MIC interface
    • MIC activity detect & interrupt allows processor to sleep
  • 2W stereo (2 x 2W) class D/AB speaker driver
  • Capless Class W headphone drivers
    • Integrated charge pump
    • 5.3 mW total power for DAC playback to headphones
  • 4 line outputs (single-ended or differential)
  • BTL earpiece driver
  • Digital audio interfaces for multi-processor architecture
    • Asynchronous stereo duplex sample rate conversion
    • Powerful mixing and digital loopback functions
  • ReTune™ Mobile 5-band, 6-channel parametric EQ
  • Programmable dynamic range controller
  • Dual FLL provides all necessary clocks
    • Self-clocking modes allow processor to sleep
    • All standard sample rates from 8 kHz to 96 kHz
  • Active noise reduction circuits
    • DC offset correction removes pops and clicks
    • Ground loop noise cancellation
  • Integrated LDO regulators
  • 72-ball W-CSP package (4.511 x 4.023 x 0.7mm)

Parametric Specifications

ADCs 2
DACs 4
DAC Dynamic Range (dB) 100
ADC Dynamic Range (dB) 94
DAC THD+N (dB) -86
ADC THD+N (dB) -87
Sample Rate (kHz) 96
Package 72 WLCSP

Technical Documents

WM8994 Product Datasheet

Dec 7, 2016, v4.5 : 6166 Kb

WM8994 Product Brief

May 1, 2012, Rev 4.1 : 667 Kb

Software and Tools

Device Pack for WM8994EV1M

v3.0 : 14047 Kb


v3.8.1.2 : 40.3 Mb


Comprehensive Solutions