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®
AC ‘97 SoundMAX Codec
AD1981A
AC ’97 2.2-COMPLIANT CODEC
High Quality CD Input with Ground Sense
Mono Output for Speakerphone or Internal Speaker
Power Management Support
48-Lead LQFP Package
FEATURES
S/PDIF Output, 20 Bits Data Format, Supporting
48 kHz and 44.1 kHz Sample Rates
Integrated Stereo Headphone Amplifier
Variable Sample Rate Audio
External Audio Power-Down Control
Greater than 90 dB Dynamic Range
16-Bit Stereo Full-Duplex Codec
20-Bit DAC Input
Three Analog Line-Level Stereo Inputs for
LINE-IN, AUX, and CD
Mono Line-Level Phone Input
Mono MIC Input with Built-In Programmable Preamp
ENHANCED FEATURES
Built-in Digital Equalizer Function for Optimized
Speaker Sound
Full Duplex Variable Sample Rates from 7040 Hz to 48 kHz
with 1 Hz Resolution
Jack Sense Pins Provide Automatic Output Switching
Software-Programmed V REFOUT Output for Microphone
Bias and External Power Amp
Split Power Supplies: 3.3 V Digital and 5 V Analog
Multiple Codec Configuration Options
FUNCTIONAL BLOCK DIAGRAM
VREF
VREFOUT
XTL_OUT
XTL_IN
ID1
ID0
MIC PREAMP
AD1981A
MIC_IN
G
VREF
CD_L
CD_GND
CD_R
CD
DIFF AMP
XTAL OSCILLATOR
A/D SAMPLE RATE
GENERATOR
PLL CLOCK
GENERATOR
G
M
16-BIT ⌺-⌬ A/D
CONVERTER
G
M
16-BIT ⌺-⌬ A/D
CONVERTER
G
M
16-BIT ⌺-⌬ A/D
CONVERTER
G
M
16-BIT ⌺-⌬ A/D
CONVERTER
M
GA
20-BIT ⌺-⌬ D/A
CONVERTER
SPKR
EQ
M
GA
20-BIT ⌺-⌬ D/A
CONVERTER
SPKR
EQ
LINE_IN
HP
LINE_OUT_L
M
M
MONO_OUT
M
GA
A
A
GA
GA
GA
M
M
M
GA
M
M
M
M
M
GA
GA
GA
AC ’97 CONTROL REGISTERS
A
M
A
M
HP_OUT_R
HP
EQ COEFF STORAGE
ANALOG
MUTE
CONTROL
LOGIC
M
M
LINE_OUT_R
D/A SAMPLE RATE
GENERATOR
A
SELECTOR
HP_OUT_L
LINK PORT/
ID SELECT
AC ’97 LINK SIGNALS
PHONE_IN
G
AC ’97 SERIAL INTERFACE
SELECTOR
AUX
KEY:
G = GAIN
A = ATTENUATE
M = MUTE
JACK SENSE
EAPD
SPDIF
JS1
EAPD
SPDIF
JS0
SoundMAX is a registered trademark of Analog Devices, Inc.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2002
