Mono Codec with Video Buffer

The WM8944 is a highly integrated low power hi-fi codec designed for portable devices such as digital still cameras. Up to 2 analog inputs may be connected, and a stereo digital microphone interface is also provided. Flexible output mixing options support single-ended and differential configurations, with outputs derived from the digital audio paths or from analog bypass paths. Mono line output and mono BTL headphone/speaker drive is supported. Flexible digital mixing and powerful DSP functions are available. Programmable filters and other processes may be applied to the ADC and DAC signal paths simultaneously. The DSP functions include 5 notch filters, 5-band EQ, dynamic range control and the Cirrus Logic ReTune™ feature. The ReTune™ feature is a sophisticated digital filter that can compensate for imperfect characteristics of the housing, loudspeaker or microphone components in an application. The ReTune™ algorithm can provide acoustic equalisation and selective phase (delay) control of specific frequency bands. The WM8944 is controlled via a I²C or SPI interface. Additional functions include digital beep generator, video buffer, programmable GPIO functions, Frequency Locked Loop (FLL) for flexible clocking support and integrated LDO for low noise supply regulation. The WM8944 is supplied in 25-ball W-CSP package, ideal for portable systems.



  • Hi-fi audio codec
    • 94 dB SNR during ADC recording (‘A’ weighted)
    • 96 dB SNR during DAC playback (‘A’ weighted)
  • 2 analog audio inputs
  • Integrated bias reference for electret microphones
  • Digital microphone interface (Stereo)
  • Powerful digital mixing / DSP functions:
    • 5-notch filters
    • 5-band equalizer (EQ)
    • ReTune™ parametric filter
    • Dynamic range control and noise gate
    • Low-pass/High-pass filters
    • Direct Form 1 (DF1) programmable digital filter
    • 3D stereo enhancement (for digital mic input)
  • Digital beep generator
  • Mono line output
  • Mono BTL headphone/speaker output driver
  • I²S digital audio interface - sample rates 8kHz to 48kHz
  • Frequency Locked Loop (FLL) frequency conversion / filter
  • Video buffer function
  • Integrated LDO low-noise voltage regulator
  • 25-ball W-CSP package (2.38 x 2.38 x 0.7mm, 0.5mm pitch)

Parametric Specifications

DACs 1
ADCs 1
DAC SNR (dB) 96
ADC SNR (dB) 94
DAC THD+N (dB) -78
ADC THD+N (dB) -77
Sample Rate (kHz) 8-48
Analog Power Supply (V) 2.4-3.6
Power Consumption (mW) 9.9-54.7
Package 25 W-CSP

Technical Documents

6229 EV1 REV2 Schematic and Layout

Feb 19, 2019, REV 2 : 2.1 Mb

WM8944B Product Datasheet

Jul 10, 2018, v4.4 : 2.7 Mb

WM8944B_6229_CS25_M_REV1 Schematic Layout

Apr 1, 2010, REV 1 : 936 Kb

WM984X_6229_CS36_M_REV1 Example Configuration

Aug 1, 2009, Rev 1.0 : 14 Mb

Software and Tools

WM8944B Setup

Feb 19, 2019, Rev 1.5 : 1.5Mb


Comprehensive Solutions