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DESCRIPTION
The WM8945 is a highly integrated low power hi-fi CODEC
designed for portable devices such as digital still cameras.
Up to 4 analogue inputs may be connected; a digital microphone
interface is also provided. Flexible output mixing options support
single-ended and differential configurations, with outputs derived
from the digital audio paths or from analogue bypass paths.
Mono line output and mono BTL headphone/speaker drive is
supported.
Flexible digital mixing and powerful DSP functions are available.
Programmable filters and other processes may be applied to the
ADC or DAC signal paths. The DSP functions include 5 notch
filters, 5-band EQ, dynamic range control and the Wolfson
ReTune™ feature.
The ReTune™ feature is a sophisticated digital filter that can
compensate for imperfect characteristics of the housing,
loudspeaker or microphone components in an application. The
ReTune™ algorithm can provide acoustic equalisation and
selective phase (delay) control of specific frequency bands.
The WM8945 is controlled via an I2C or SPI interface. Additional
functions include 4-wire Touch Panel controller, Auxiliary ADC,
Digital beep generator, Video buffer, programmable GPIO
functions, Frequency Locked Loop (FLL) for flexible clocking
support and integrated LDO for low noise supply regulation.
The WM8945 is supplied in 36-ball W-CSP package, ideal for
portable systems.
DCVDD
DBVDD
SPKVDD
VBIN
WM8945
Mono Low-Power CODEC with
Video Buffer and Touch Panel Controller
FEATURES
Hi-fi audio CODEC
- 94dB SNR during ADC recording (‘A’ weighted)
- 96dB SNR during DAC playback (‘A’ weighted)
4 analogue audio inputs
Integrated bias reference for electret microphones
Digital microphone interface
Powerful digital mixing / DSP functions:
- 5-notch filters
- 5-band equalizer (EQ)
- ReTune™ parametric filter
- Dynamic range control and noise gate
- Low-pass/High-pass filters
- Direct Form 1 (DF1) programmable digital filter
Digital beep generator
Mono line output
Mono BTL headphone/speaker output driver
I2S digital audio interface - sample rates 8kHz to 48kHz
Frequency Locked Loop (FLL) frequency conversion / filter
Video buffer function
4-wire Touch Panel interface controller
Auxiliary ADC for DC measurement or battery monitoring
Integrated LDO low-noise voltage regulator
36-ball W-CSP package (2.96 x 3.06 x 0.7mm, 0.5mm pitch)
APPLICATIONS
Digital Still Cameras (DSC)
Multimedia phones
VBREFR
VBOUT
XP
YN
YP
XN
AUX1
AUX2
TOUCH PANEL
INTERFACE
AUX ADC
CURRENT MODE
VIDEO BUFFER
W
WM8945
LINEOUTL
IN1L/DMICDAT
IN2L
Analogue Mic
Mux / PGA
ADC L
ADC /
Record
Digital
Filters
DSP Core
(Re-Tune EQ,
Dynamic Range
Control)
DAC L
-1
DAC
Digital
Filters
OUTPUT
MIXERS
SPKOUTL
DMICDAT
DMICCLK
(GPIO)
Digital Mic
Interface
SPKOUTR
Digital Beep
Generator
DIGITAL AUDIO
INTERFACE
MICBIAS
Reference
LDO
FLL
CONTROL
INTERFACE
GPIO
LDOVOUT
LDOVDD
VMIDC
ADCDAT
DACDAT
LRCLK
BCLK
WOLFSON MICROELECTRONICS plc
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SDA
SCLK
CS/GPIO2
CIFMODE/GPIO3
SDOUT/GPIO4
Production Data, May 2011, Rev 4.1
Copyright
2011
Wolfson Microelectronics plc
GPIO1
MCLK
GND