WM8955L
STEREO DAC FOR PORTABLE AUDIO APPLICATIONS
DESCRIPTION
The WM8955L is a low power, high quality stereo DAC with
integrated headphone and loudspeaker amplifiers, designed
to reduce external component requirements in portable digital
audio applications.
The on-chip headphone amplifiers can deliver 40mW into a
16Ω load. Advanced on-chip digital signal processing
performs bass and treble tone control.
The WM8955L can operate as a master or a slave, and
includes an on-chip PLL. It can use most master clock
frequencies commonly found in portable systems, including
USB, GSM, CDMA or PDC clocks, or standard 256f
s
clock
rates. Different audio sample rates such as 48kHz, 44.1kHz,
8kHz and many others are supported.
The WM8955L operates on supply voltages from 1.8V up to
3.6V, although the digital core can operate on a separate
supply down to 1.42V, saving power. Different sections of the
chip can also be powered down under software control.
The WM8955L is supplied in a very small and thin 5x5mm
QFN package, ideal for use in hand-held and portable
systems.
FEATURES
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DAC SNR 98dB, THD -95dB (‘A’ weighted @ 48kHz, 3.3V)
On-chip 400mW BTL Speaker Driver (mono)
On-chip Headphone Driver
°
40mW output power on 16Ω / 3.3V
°
THD –80dB at 20mW, SNR 90dB with 16Ω load
Stereo and Mono Line-in mix into DAC output
Separately Mixed Stereo and Mono Outputs
Digital Tone Control and Bass Boost
Low Power
°
Down to 7mW for stereo playback (1.8V / 1.5V supplies)
°
10µW Standby Mode
Low Supply Voltages
°
Analogue 1.8V to 3.6V
°
Digital core: 1.42V to 3.6V
°
Digital I/O: 1.42V to 3.6V
Master clocks supported: GSM, CDMA, PDC, USB or
standard audio clocks
Audio sample rates supported: 8, 11.025, 12, 16, 22.05, 24,
32, 44.1, 48, 88.2, 96kHz
32-pin QFN package, 5x5x0.9mm size, 0.5mm lead pitch
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APPLICATIONS
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Smartphone / Multimedia Phone
Digital Audio Player
BLOCK DIAGRAM
MONOIN+
MONOIN-
LINEINL
LINEINR
HPGND
HPVDD
-1
DBVDD
DCVDD
DGND
W
WM8955L
LEFT
LD2LO MIXER
DIFF. IN
LI2LO
MONOOUT
ROUT1
VREF
M
U
X
OUT3
LOUT1
CSB
SDIN
SCLK
MODE
RD2LO
CONTROL
INTERFACE
DAC
DIGITAL
FILTERS
VREF
LD2MO
MONO
MIXER
MI2LO
LI2MO
LOUT1VOL
MONOOUT
RD2MO
RI2MO
MI2RO
MONOVOL
BCLK
DACLRC
DACDAT
DIGITAL
AUDIO
INTERFACE
TONE
CONTROL
DAC
RIGHT
LD2RO MIXER
ROUT1
MCLK
DIV2
MCLK
SEL
RD2RO
RI2RO
ROUT1VOL
LOUT2
PLL
VREF
CLKOUT
SEL
-1
50K
50K
LOUT2VOL
ROUT2
INV
MCLK
f/2
Loudspeaker
L - (-R)
= L+R
ROUT2
CLKOUT
CLKOUT
DIV2
f/2
ROUT2VOL
AVDD
AGND
VREF
VMID
HPDETECT
WOLFSON MICROELECTRONICS PLC
www.wolfsonmicro.com
Product Preview, May 2003, Rev 0.4
Copyright
2003
Wolfson Microelectronics plc
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
