WM8944B
Mono Low-Power CODEC with Video Buffer
DESCRIPTION
FEATURES
Hi-fi audio CODEC
The WM8944B is a highly integrated low power hi-fi CODEC
designed for portable devices such as digital still cameras.
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94dB SNR during ADC recording (‘A’ weighted)
96dB SNR during DAC playback (‘A’ weighted)
Up to 2 analogue inputs may be connected; a stereo 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.
2 analogue audio inputs
Integrated bias reference for electret microphones
Digital microphone interface (Stereo)
Powerful digital mixing / DSP functions:
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5-notch filters
5-band equalizer (EQ)
ReTune™ parametric filter
Dynamic range control and noise gate
Low-pass/High-pass filters
Flexible digital mixing and powerful DSP functions are
available. Programmable filters and other processes may be
applied to the ADC and DAC signal paths simultaneously. The
DSP functions include 5 notch filters, 5-band EQ, dynamic
range control and the ReTune™ feature.
Direct Form 1 (DF1) programmable digital filter
3D stereo enhancement (for digital mic input)
Digital beep generator
Mono line output
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.
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
Integrated LDO low-noise voltage regulator
25-ball W-CSP package (2.41 x 2.41 x 0.55mm, 0.5mm pitch)
The WM8944B is controlled via a I2C or SPI interface.
Additional functions include Digital beep generator, Video
buffer, programmable GPIO functions, Frequency Locked
Loop (FLL) for flexible clocking support and integrated LDO
for low noise supply regulation.
APPLICATIONS
Digital Still Cameras (DSC)
Multimedia phones
The WM8944B is supplied in 25-ball W-CSP package, ideal
for portable systems.
DCVDD
DBVDD
SPKVDD
VBIN
VBREFR
VBOUT
WM8944B
CURRENT MODE
VIDEO BUFFER
AUX
LINEOUT
Analogue Mic
Mux / PGA
IN1/DMICDAT
ADC L
DAC L
DSP Core
(L/HPF, 3D
Surround,
5-notch filter,
Re-Tune EQ,
Dynamic Range
Control)
OUTPUT
MIXERS
-1
SPKOUTP
SPKOUTN
ADC /
DAC
Digital
Filters
Record
Digital
Filters
DMICDAT
Digital Mic
Interface
DMICCLK
(GPIO)
Digital Beep
Generator
DIGITAL AUDIO
INTERFACE
CONTROL
INTERFACE
FLL
GPIO
Reference
LDO
MICBIAS
Rev 4.3
NOV ‘16
Copyright Cirrus Logic, Inc., 2010–2016
http://www.cirrus.com
(All Rights Reserved)