WM8955L Datasheet, PDF (1/43 Pages) Wolfson Microelectronics plc – STEREO DAC FOR PORTABLE AUDIO APPLICATIONS

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 256fs 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.
BLOCK DIAGRAM
FEATURES
• 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
APPLICATIONS
• Smartphone / Multimedia Phone
• Digital Audio Player
CSB
SDIN
SCLK
MODE
BCLK
DACLRC
DACDAT
MCLK
CLKOUT
DBVDD DCVDD DGND
W
WM8955L
DIFF. IN
LEFT
LD2LO ^MIXER
LI2LO
CONTROL
INTERFACE
DIGITAL
FILTERS
DAC
RD2LO
MONO
MIXER
LD2MO
MI2LO
LI2MO
DIGITAL
AUDIO
INTERFACE
TONE
CONTROL
DAC
MCLK
DIV2
f/2
PLL
f/2
CLKOUT
DIV2
MCLK
SEL
CLKOUT
SEL
RD2MO
RIGHT
LD2RO ^MIXER
RI2MO
MI2RO
RD2RO
RI2RO
VREF
50K 50K
MONOOUT
M
ROUT1
U
VREF
X
-1
OUT3
LOUT1VOL
LOUT1
MONOVOL
MONOOUT
ROUT1VOL
ROUT1
LOUT2
LOUT2VOL
-1 ROUT2
INV
ROUT2
ROUT2VOL
Loudspeaker
L - (-R)
= L+R
HPDETECT
WOLFSON MICROELECTRONICS PLC
www.wolfsonmicro.com
Product Preview, May 2003, Rev 0.4
Copyright 2003 Wolfson Microelectronics plc