WM9712: CODEC with touchpanel controller


The WM9712L is a highly integrated input / output device designed for mobile computing and communications. The device can connect directly to a 4-wire or 5-wire touchpanel, mono or stereo microphones, stereo headphones and a mono speaker, reducing total component count in the system. Additionally, phone input and output pins are provided for seamless integration with wireless communication devices. 

The WM9712L also offers up to four auxiliary ADC inputs for analogue measurements such as temperature or light, and five GPIO pins for interfacing to buttons or other digital devices. To monitor the battery voltage in portable systems, the WM9712L has two uncommitted comparator inputs. 

All device functions are accessed and controlled through a single AC-Link interface compliant with the AC’97 standard. Additionally, the WM9712L can generate interrupts to indicate pen down, pen up, availability of touchpanel data, low battery, dead battery, and GPIO conditions. 

The WM9712L operates at supply voltages from 1.8 to 3.6 Volts. Each section of the chip can be powered down under software control to save power. The device is available in a small leadless 7x7mm QFN package, ideal for use in hand-held portable systems.


  • AC’97 Rev 2.2 compatible stereo codec
    - DAC SNR 94dB, THD –87dB
    - ADC SNR 92dB, THD –87dB
    - Variable Rate Audio, supports all WinCE sample rates
    - Tone Control, Bass Boost and 3D Enhancement
  • On-chip 45mW headphone driver
  • On-chip 400mW mono speaker driver
  • Stereo, mono or differential microphone input
    - Automatic Level Control (ALC)
  • Auxiliary mono DAC (ring tone or DC level generation)
  • Seamless interface to wireless chipset
  • Resistive touchpanel interface
    - Supports 4-wire and 5-wire panels
    - 12-bit resolution, INL +2 LSBs (<0.5 pixels)
    - X, Y and touch-pressure (Z) measurement
    - Pen-down detection supported in Sleep Mode
  • Up to 5 GPIO pins
  • 2 comparator inputs for battery monitoring
  • Up to 4 auxiliary ADC inputs
  • 1.8V to 3.6V supplies
  • 7x7mm QFN