AD1981B
PIN FUNCTION DESCRIPTIONS
Pin No.
DIGITAL I/O
2
3
5
6
8
10
11
48
Mnemonic
XTL_IN
XTL_OUT
SDATA_OUT
BIT_CLK
SDATA_IN
SYNC
RESET
SPDIF
ID0
ID1
I/O
I
O
I
O/I
O
I
I
O
Function
Crystal Input (24.576 MHz) or External Clock Input.
Crystal Output.
AC-Link Serial Data Output, AD1981B Data Input Stream.
AC-Link Bit Clock Output (12.288 MHz) or Bit Clock Input if Secondary Mode
Selected.
AC-Link Serial Data Input, AD1981B Data Output Stream.
AC-Link Frame Sync.
AC-Link Reset, AD1981B Master Hardware Reset.
S/PDIF Output.
CHIP SELECTS (These pins can also be used to select an external clock. See Table IX.)
45
46
I
I
Chip Select Input 0 (Active Low). This pin can also be used as the chain input from
a secondary codec.
Chip Select Input 1 (Active Low).
JACK SENSE AND EAPD
17
16
47
ANALOG I/O
13
14
15
18
19
20
21
22
23
24
35
36
37
39
41
PHONE_IN
AUX_L
AUX_R
CD_L
CD_GND_REF
CD_ R
MIC1
MIC2
LINE_IN_L
LINE_IN_R
LINE_OUT_L
LINE_OUT_R
MONO_OUT
HP_OUT_L
HP_OUT_R
I
I
I
I
I
I
I
I
I
I
O
O
O
O
O
Phone Input. Mono input from telephony subsystem speaker phone or handset.
Auxiliary Input Left Channel.
Auxiliary Input Right Channel.
CD Audio Left Channel.
CD Audio Analog Ground Reference for Differential CD Input.
CD Audio Right Channel.
Microphone 1 Input (Mono) or Left Channel when 2-Channel Mode
Selected (Stereo MIC).
Microphone 2 Input (Mono) or Right Channel when 2-Channel Mode
Selected (Stereo MIC).
Line In Left Channel.
Line In Right Channel.
Line Out (Front) Left Channel.
Line Out (Front) Right Channel.
Monaural Output to Telephony Subsystem Speakerphone.
Headphone Left Channel Output.
Headphone Right Channel Output.
JS0
JS1
EAPD
I
I
O
Jack Sense 0 Input.
Jack Sense 1 Input.
External Amp Power-Down Control.
FILTER/REFERENCE (These signals are connected to resistors, capacitors, or specific voltages.)
27
28
29
30
31
32
V
REF
V
REFOUT
AFILT1
AFILT2
AFILT3
AFILT4
O
O
O
O
O
O
Voltage Reference Filter.
Voltage Reference Output 5 mA Drive (Intended for MIC Bias and Power Amp Bias).
Antialiasing Filter Capacitor—ADC Right Channel.
Antialiasing Filter Capacitor—ADC Left Channel.
Antialiasing Filter Capacitor—Mixer ADC Right Channel.
Antialiasing Filter Capacitor—Mixer ADC Left Channel.
POWER AND GROUND SIGNALS
1
4
7
9
25
26
38
40
43
44
34
33
NO CONNECTS
12
42
NC
NC
No Connect.
No Connect.
DV
DD
1
DV
SS
1
DV
SS
2
DV
DD
2
AV
DD
1
AV
SS
1
AV
DD
2
AV
SS
2
AV
DD
3
AV
SS
3
AV
DD
4
AV
SS
4
I
I
I
I
I
I
I
I
I
I
I
I
Digital V
DD
3.3 V.
Digital GND.
Digital GND.
Digital V
DD
3.3 V.
Analog V
DD
5.0 V.
Analog GND.
Analog V
DD
5.0 V.
Analog GND.
Analog V
DD
5.0 V.
Analog GND.
Analog V
DD
5.0 V.
Analog GND.
–8–
REV. B
AD [ ANALOG DEVICES ]
