WM9705
Multimedia AC’97 CODEC with
Integrated Touch Screen Controller
DESCRIPTION
FEATURES
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AC’97 rev2.2 compliant codec with pen digitiser
The WM9705 is a high-quality stereo audio codec with an
integrated touch screen controller.
18-bit stereo audio codecs
On-chip sample rate conversion
Multiple channel input mixer
The audio section is compliant with the Intel AC’97 Rev 2.2
specification. It performs full-duplex 18-bit codec functions and
supports variable sample rates from 8 to 48k samples/s with
high signal to noise ratio. Optional AC’97 features include 3D
sound enhancement, line-level outputs, stereo buffered
headphone outputs, hardware sample rate conversion,
primary/secondary mode operation and S/PDIF output.
Headphone auto-detect, I2S output and headphone buffer on the
mono output are included.
S/PDIF digital audio output
Headphone drivers on AUX and MONO outputs
4-wire touch screen interface with co-ordinate and
pressure measurement, and pen-down detection
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Wake-up from sleep mode on pen down
3V to 5V operation
Extensive power management features including hardware
power down option
Additionally, the WM9705 integrates a complete 4-wire touch
screen controller, including on-chip screen drivers, pen-down
detection feature, and pressure measurement capability.
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Standard AC’97 pinout in 48-pin TQFP package or 48-pin
QFN package.
A 5-pin digital bi-directional AC-Link serial interface allows
transfer of control data and DAC and ADC words to and from APPLICATIONS
the AC’97 controller. The WM9705 is fully operable on 3V or 5V
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Personal Digital Assistants and ‘Smartphones’
or mixed 3/5V supplies, and is packaged in the industry
standard 48-pin TQFP package with 7mm body size, or in a
smaller 7 × 7 × 0.9mm QFN.
PocketPC systems
BLOCK DIAGRAM
DGND1
DVDD1
DGND2
DVDD2
CX3D1 CX3D2
HPGND
HPVDD
ADCNDAC
(Reg 5Ch)
MUX
16 / 32Ohm
headphone
LINEINVOL (Reg 10h)
HPVOL
(Reg 04h)
CDVOL (Reg 12h)
M
U
X
HPOUTL
HPOUTR
HPGND
MICVOL (Reg 0Eh)
3D
HPND
(Reg 5Ch)
MIXVOL
(Reg 72h)
VID
RECORD
GAIN
(Reg 1Ch)
DIGITAL
FILTERS
AUX
ADC
L
DAC
L
LINEINL
LINEINR
CDL
CDGND
CDR
M
U
X
PHONE
Σ ∆
LINEOUTL
LINEOUTR
MODULATION
DACVOL
(Reg 18h)
MIC BOOST
(Reg 0Eh)
VID
AUX
ADC
R
DAC
R
MIC SELECT
(Reg 20h)
VARIABLE
RATE AUDIO
MASTER VOL
(Reg 02h)
RECORD
SELECT
(Reg 1Ah)
POP
(Reg 20h)
M
U
X
MIC2
0/20
dB
MIX
M
U
X
MIC1
(Reg 20h)
M
U
X
headset autodetect
HPOUTL
(Reg 0Ah)
(Reg 0Ch)
W
WM9705
MONO_OUT
(TX)
PCBEEP
PHONE
SAR
ADC
M
U
X
AUXADC
BMON
MONO VOL
(Reg 06h)
ADCSEL
PSEL
(Reg 5Ch)
PEN DOWN
TOUCH PANEL
SWITCH MATRIX
VREF
VREFOUT
AC'97
INTERFACE
CLOCK
OSC
CONTROL LOGIC
VID
AUX
24.576MHz
4-wire resistive
touchpanel
WOLFSON MICROELECTRONICS plc
Production Data, December 2003, Rev 4.0
Copyright 2003 Wolfson Microelectronics plc
www.wolfsonmicro.com