98/94 dB Mono Codec with Speaker Driver

The WM8974 is a low power, mono codec with integrated support for a differential or single ended mic, and includes drivers for speakers or headphone, as well as the mono line output. Separate microphone and headphone amplifiers are not required, and advanced Delta-Sigma converters are used along with digital decimation and interpolation filters to give high quality audio at sample rates from 8 to 48 ks/s. Additional digital filtering options are available in the ADC path to provide application filtering such as 'wind noise reduction'. An advanced mixed-signal ALC function with noise gate also is provided. An on-chip PLL is provided to generate the required main clock from an external reference clock. The PLL clock can also be output if required elsewhere in the system. Different sections of the chip can also be powered down under software control by way of the selectable two or three wire control interface.



Mono/Stereo Codecs


  • Mono codec
  • Audio sample rates:8, 11.025, 16, 22.05, 24, 32, 44.1, 48 kHz
  • DAC SNR 98 dB, THD -84 dB (‘A’-weighted @ 8 – 48ks/s)
  • ADC SNR 94 dB, THD -83 dB (‘A’-weighted @ 8 – 48ks/s)
  • On-chip headphone/speaker driver with ‘cap-less’ connect
    • 40㎽ output power into 16Ω / 3.3V SPKVDD
    • BTL speaker drive 0.9W into 8Ω / 5V SPKVDD
  • Additional mono line output
  • Multiple analog or ‘Aux’ inputs, plus analog bypass path
  • Mic preamps
  • Differential or single-ended microphone interface
    • Programmable preamp gain
    • Psuedo-differential inputs with common mode rejection
    • Programmable ALC / noise gate in ADC path
  • Low-noise bias supplied for electret microphones
  • 5 band EQ (record or playback path)
  • Digital playback limiter
  • Programmable ADC high pass filter (wind noise reduction)
  • Programmable ADC Notch Filter
  • On-chip PLL
  • Low power, low voltage
    • 2.5V to 3.6V (digital: 1.71V to 3.6V)
    • Power consumption <10mA all-on 48ks/s mode
  • 4x4x0.9mm 24 lead QFN package

Parametric Specifications

Channels In 1
Channels Out 1
DAC THD+N (dB) -84 (THD)
ADC THD+N (dB) -83 (THD)
Analog Power Supply (V) 2.5-3.6
Digital Power Supply (V) 1.71-3.6
Logic Power Supply (V) 2.5-5.5
Operational Power Consumption (mW) <10mA
Package 24 QFN

Software and Tools


Jan 14, 2021, v3.12.0.5 : 43.2 Mb


Comprehensive Solutions