REV. 0

AD1981A

–7–

PIN FUNCTION DESCRIPTIONS

Pin No.

Mnemonic

I/O

Function

DIGITAL I/O

2

XTL_IN

I

Crystal Input (24.576 MHz) or External Clock Input

3

XTL_OUT

O

Crystal Output

5

SDATA_OUT

I

AC-Link Serial Data Output, AD1981A Data Input Stream

6

BIT_CLK

O/I

AC-Link Bit Clock Output (12.288 MHz) or Bit Clock Input

if Secondary Mode Selected

8

SDATA_IN

O

AC-Link Serial Data Input, AD1981A Data Output Stream

10

SYNC

I

AC-Link Frame Sync

11

RESET

I

AC-Link Reset, AD1981A Master H/W Reset

48

SPDIF

O

S/PDIF Output

CHIP SELECTS (These pins can also be used to select an external clock. See Table II.)

45

ID0

I

Chip Select Input 0 (Active Low)

This pin can also be used as the chain input from a secondary Codec.

46

ID1

I

Chip Select Input 1 (Active Low)

JACK SENSE AND EAPD

17

JS0

I

JACK SENSE 0 Input

16

JS1

I

JACK SENSE 1 Input

47

EAPD

O

External Amp Power-Down Control

ANALOG I/O

13

PHONE_IN

I

PHONE Input. Mono input from telephony subsystem

speaker phone or handset.

14

AUX_L

I

AUXILIARY Input Left Channel

15

AUX_R

I

AUXILIARY Input Right Channel

18

CD_L

I

CD Audio Left Channel

19

CD_GND_REF

I

CD Audio Analog Ground Reference for Differential CD Input

20

CD_ R

I

CD Audio Right Channel

21

MIC_IN

I

Microphone Input (Mono)

23

LINE_IN_L

I

Line In Left Channel

24

LINE_IN_R

I

Line In Right Channel

35

LINE_OUT_L

O

Line Out (Front) Left Channel

36

LINE_OUT_R

O

Line Out (Front) Right Channel

37

MONO_OUT

O

Monaural Output to Telephony Subsystem Speakerphone

39

HP_OUT_L

O

Headphone Left Channel Output

41

HP_OUT_R

O

Headphone Right Channel Output

FILTER/REFERENCE (These signals are connected to resistors, capacitors, or specific voltages.)

27

O

Voltage Reference Filter

28

O

Voltage Reference Output 5 mA Drive (Intended for Mic Bias

and Power Amp Bias)

29

AFILT1

O

Antialiasing Filter Capacitor—ADC Right Channel

30

AFILT2

O

Antialiasing Filter Capacitor—ADC Left Channel

31

AFILT3

O

Antialiasing Filter Capacitor—Mixer ADC Right Channel

32

AFILT4

O

Antialiasing Filter Capacitor—Mixer ADC Left Channel

POWER AND GROUND SIGNALS

I

I

Digital GND

I

Digital GND

I

25

I

26

I

Analog GND

33

I

Analog GND

34

I

38

I

40

I

Analog GND

43

I

44

I

Analog GND

NO CONNECTS

12

NC

No Connect

22

NC

No Connect

42

NC

No Connect