AD1981B
PIN FUNCTION DESCRIPTIONS
Function
Pin No.
Mnemonic
I/O
DIGITAL I/O
2
3
5
6
XTL_IN
I
O
I
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.
XTL_OUT
SDATA_OUT
BIT_CLK
O/I
8
SDATA_IN
SYNC
RESET
SPDIF
O
I
I
O
10
11
48
CHIP SELECTS (These pins can also be used to select an external clock. See Table IX.)
45
46
ID0
ID1
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
JS0
I
Jack Sense 0 Input.
JS1
I
Jack Sense 1 Input.
EAPD
O
External Amp Power-Down Control.
ANALOG I/O
13
14
15
18
19
20
21
PHONE_IN
AUX_L
I
I
I
I
I
I
I
Phone Input. Mono input from telephony subsystem speaker phone or handset.
Auxiliary Input Left Channel.
AUX_R
Auxiliary Input Right Channel.
CD_L
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.
CD_GND_REF
CD_ R
MIC1
22
MIC2
I
23
24
35
36
37
39
41
LINE_IN_L
LINE_IN_R
LINE_OUT_L
LINE_OUT_R
MONO_OUT
HP_OUT_L
HP_OUT_R
I
I
O
O
O
O
O
FILTER/REFERENCE (These signals are connected to resistors, capacitors, or specific voltages.)
27
28
29
30
31
32
VREF
O
O
O
O
O
O
Voltage Reference Filter.
VREFOUT
AFILT1
AFILT2
AFILT3
AFILT4
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
DVDD1
I
I
I
I
I
I
I
I
I
I
I
I
Digital VDD 3.3 V.
Digital GND.
4
DVSS
DVSS
1
2
7
9
Digital GND.
DVDD2
AVDD
AVSS
AVDD2
AVSS
AVDD
AVSS3
Digital VDD 3.3 V.
Analog VDD 5.0 V.
Analog GND.
Analog VDD 5.0 V.
Analog GND.
Analog VDD 5.0 V.
Analog GND.
Analog VDD 5.0 V.
Analog GND.
25
26
38
40
43
44
34
33
1
1
2
3
AVDD
4
AVSS
4
NO CONNECTS
12
42
NC
NC
No Connect.
No Connect.
REV. B
–8–