REV. B
a
AD1981B
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AC ’97 SoundMAX
®

Codec
FUNCTIONAL BLOCK DIAGRAM
AM
MIC1
MIC2
PHONE_IN
CD_L
CD_GND
CD_R
AUX_L
AUX_R
LINE_IN_L
MIC PREAMP
CD
DIFF AMP
MONO_OUT
HP_OUT_L HP
MZ LINE_OUT_L
MZ LINE_OUT_R
HP_OUT_R HP
OUTPUT SELECT
OR
G = GAIN
A = ATTENUATION
M = MUTE
Z = HIGH Z
16-BIT
H9018-H9004 ADC
GA
16-BIT
H9018-H9004 ADC
PCM FRONT
DAC RATE
M
16-BIT
H9018-H9004 ADC
M
16-BIT
H9018-H9004 ADC
PCM L/R
ADC RATE
RECORD
SELECT
OR
V
REF
G
V
REFOUT
LINE_IN_R
CODEC CORE
ADC
AND
DAC
SLOT
LOGIC
EQ CORE ST
ORA
GE
AC '97
CONTROL
REGISTERS
EAPD
PLL
XTL_OUT XTL_IN SPDIF
SPDIF
TX
ID0
ID1
RESET
SYNC
BIT_CLK
SDATA_OUT
SDATA_IN
JS0 JS1 EAPD
AD1981B
G
G
2CMIC
MIX
AM
A
A
AM
M
GA
M
GA
M
GA
M
GA
M
GA
M
GA
M
GA
M
GA
M
M
GAM
M
BYP
ASS
EQ
BYP
ASS
EQ
G
G
VOLTAGE
REFERENCE
ANALOG MIXING
CONTROL LOGIC
20-BIT
H9018-H9004 DAC
20-BIT
H9018-H9004 DAC
AC
'
97 INTERF
A
CEM
G M
G
MS
FEATURES
AC ’97 2.3 COMPATIBLE 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
Stereo Full-Duplex Codec
20-Bit PCM DAC
3 Analog Line-Level Stereo Inputs for
Line-In, AUX, and CD
Mono Line-Level Phone Input
Dual MIC Input with Built-In Programmable Preamp
High Quality CD Input with Ground Sense
Mono Output for Speakerphone or Internal Speaker
Power Management Support
48-Lead LQFP Package, Lead-Free Available
ENHANCED FEATURES
Stereo MIC Preamps Support
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 Biasing
Microphone and External Power Amp
Split Power Supplies: 3.3 V Digital and 5 V Analog
Multiple Codec Configuration Options