WM2000: Handset receiver speaker driver with ambient noise cancellation


The WM2000 is a low power, high quality handset receiver speaker driver with ambient noise cancellation. Together with well designed handset acoustics, it provides enhanced voice communication quality in a noisy environment.

The device integrates into the handset output signal path with minimal architectural changes. WM2000 drives the receiver directly.

The Wolfson ANC (Ambient Noise Cancellation) engine uses an adaptive filtering algorithm which requires one or a pair of dedicated analogue microphones. The filtering algorithm can be adapted to the handset's acoustic characteristics for optimum noise cancellation performance. A dynamic control algorithm adjusts ANC parameters for variations in ambient noise levels.

High power supply rejection allows WM2000 to operate in a noisy electrical environment without degradation of signal quality. The device is controlled via registers which can be accessed using a 2-wire serial control interface. A pre-configured Internal Sequencer controls the internal hardware such that a single register write can be used to perform key analogue sequences during power up / power down or mode transition.


  • Wolfson Ambient Noise Cancellation (ANC) 
    -  Wide noise cancellation bandwidth (300Hz-2.5kHz)
    -  20dB typical ambient noise reduction (with well-designed acoustics)
    -  Dynamic control algorithm copes with extremes of ambient noise
  • Handset Receiver Speaker driver
    -  -79dB THD at 31mW into 32Ω
    -  -68dB THD at 80mW into 16Ω
    -  Pop-click minimisation
  • Two inputs
    -  Differential Microphone input for ambient noise
    -  Differential or single-ended Line input for received voice
  • Low power consumption
    -  20mW added to voice call when noise cancellation enabled
    -  68μW standby power
  • CSP25 package, -40°C to +85°C temperature range

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