WM8904 w Ultra Low Power CODEC for Portable Audio Applications DESCRIPTION FEATURES 3.0mW quiescent power consumption for DAC to The WM8904 is a high performance ultra-low power stereo headphone playback CODEC optimised for portable audio applications. DAC SNR 96dB typical, THD -86dB typical The device features stereo ground-referenced headphone ADC SNR 91dB typical, THD -80dB typical amplifiers using the Wolfson Class-W amplifier techniques - incorporating an innovative dual-mode charge pump architecture - to optimise efficiency and power consumption 2.4mW quiescent power consumption for analogue bypass during playback. The ground-referenced headphone and line playback outputs eliminate AC coupling capacitors, and both outputs include common mode feedback paths to reject ground Control write sequencer for pop minimised start-up and noise. shutdown Control sequences for audio path setup can be pre-loaded Single register write for default start-up sequence and executed by an integrated control write sequencer to reduce software driver development and minimise pops and Integrated FLL provides all necessary clocks clicks via Wolfsons SilentSwitch technology. - Self-clocking modes allow processor to sleep The analogue input stage can be configured for single - All standard sample rates from 8kHz to 96kHz ended or differential inputs. Up to 3 stereo microphone or line inputs may be connected. The input impedance is Stereo digital microphone input constant with PGA gain setting. 3 single ended inputs per stereo channel A stereo digital microphone interface is provided, with a 1 fully differential mic / line input per stereo channel choice of two inputs. Digital Dynamic Range Controller (compressor / limiter) A dynamic range controller provides compression and level control to support a wide range of portable recording Digital sidetone mixing applications. Anti-clip and quick release features offer good performance in the presence of loud impulsive noises. Ground-referenced headphone driver TM ReTune Mobile 5-band parametric equaliser with fully Ground-referenced line outputs programmable coefficients is integrated for optimization of speaker characteristics. Programmable dynamic range 32-pin QFN package (4 x 4mm, 0.4mm pitch) control is also available for maximizing loudness, protecting 36-ball WLCSP package (2.6 x 2.5mm, 6 x 6 ball grid, speakers from clipping and preventing premature shutdown 0.4mm pitch) due to battery droop. Common audio sampling frequencies are supported from a wide range of external clocks, either directly or generated APPLICATIONS via the FLL. Portable multimedia players The WM8904 can operate directly from a single 1.8V Multimedia handsets switched supply. For optimal power consumption, the digital Handheld gaming core can be operated from a 1.0V supply. Wireless headsets Mobile internet devices Netbooks WOLFSON MICROELECTRONICS plc Pre-Production, September 2012, Rev 3.3 To receive regular email updates, sign up at 100nF 20 100nF 20 100nF 20 2.2F 100nF 20 2.2F 2.2F CPVDD CPCB CPCA CPGND DAC R DAC L GPIO3* BYPASS R GPIO2* BYPASS L IRQ/GPIO1 MCLK DGND DBVDD 100nF DCVDD 100nF DACDAT LRCLK ADCDAT BCLK / GPIO4 SDA SCLK AGND AVDD 4.7F VMIDC 4.7F 100nF 4.7F WM8904 Pre-Production BLOCK DIAGRAM PP, Rev 3.3, September 2012 w 2 DECIMATION FILTERS INTERPOLATION FILTERS