DESCRIPTION

The WM8904 is a high performance ultra-low power stereo CODEC optimised for portable audio applications.

The device features stereo ground-referenced headphone amplifiers using the Wolfson ‘Class-W’ amplifier techniques incorporating an innovative dual-mode charge pump architecture to optimise efficiency and power consumption during playback. The ground-referenced headphone and line outputs eliminate AC coupling capacitors, and both outputs include common mode feedback paths to reject ground noise.

FEATURES

3.0mW quiescent power consumption for DAC to headphone playback

DAC SNR 96dB typical, THD -86dB typical

ADC SNR 91dB typical, THD -80dB typical

2.4mW quiescent power consumption for analogue bypass playback

Control write sequencer for pop minimised start-up and shutdown

Single register write for default start-up sequence

Integrated FLL provides all necessary clocks

  -  Self-clocking modes allow processor to sleep

  -  All standard sample rates from 8kHz to 96kHz

Stereo digital microphone input

3 single ended inputs per stereo channel

1 fully differential mic / line input per stereo channel

Digital Dynamic Range Controller (compressor / limiter)

Digital sidetone mixing

Ground-referenced headphone driver

Ground-referenced line outputs

32-pin QFN package (4 x 4mm, 0.4mm pitch)

36-ball WLCSP package (2.6 x 2.5mm, 6 x 6 ball grid, 0.4mm pitch)