w
DESCRIPTION
The WM8912 is a high performance ultra-low power stereo
DAC 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 outputs eliminate
headphone coupling capacitors. The outputs include
common mode feedback paths to reject ground noise.
Control sequences for audio path setup can be pre-loaded
and executed by an integrated control write sequencer to
reduce software driver development and minimise pops and
clicks via Wolfson’s SilentSwitch™ technology.
A dynamic range controller provides compression and level
control to support a wide range of portable recording
applications. Anti-clip and quick release features offer good
performance in the presence of loud impulsive noises.
ReTune
TM
Mobile 5-band parametric equaliser with fully
programmable coefficients is integrated for optimization of
speaker characteristics.
Common audio sampling frequencies are supported from a
wide range of external clocks, either directly or generated
using the integrated FLL.
The WM8912 can operate directly from a single 1.8V
switched supply. For optimal power consumption, the digital
core can be operated from a 1.0V supply.
WM8912
Ultra Low Power DAC with Headphone Driver
for Portable Audio Applications
FEATURES
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3.8mW quiescent power consumption for DAC to
headphone playback
DAC SNR 96dB typical, THD -86dB typical
Class W ground-referenced headphone driver
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28mW per channel into 30Ω at <1% THD
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32mW per channel into 15Ω at <1% THD
Dynamic range controller
ReTune™ Mobile parametric equalizer
Integrated control write sequencer for pop minimised start-
up and shutdown
Single register write for default start-up and shutdown
sequences
On-chip FLL provides all necessary clocks
DAC supports standard sample rates from 8kHz to 96kHz
32-pin QFN package (4x4mm, 0.4mm pitch)
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APPLICATIONS
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Portable multimedia players
Multimedia handsets
Handheld gaming
WOLFSON MICROELECTRONICS plc
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Production Data, September 2010, Rev 4.0
Copyright
©2010
Wolfson Microelectronics plc
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
