AD1881A

–8–

REV. 0

PIN FUNCTION DESCRIPTIONS

Digital I/O

Pin Name

LQFP

I/O

Description

XTL_IN

2

I

Crystal (or Clock) Input, 24.576 MHz.

XTL_OUT

3

O

Crystal Output.

SDATA_OUT

5

I

AC-Link Serial Data Output, AD1881A Input Stream.

BIT_CLK

6

O

AC-Link Bit Clock. 12.288 MHz Serial Data Clock. Daisy Chain Output Clock.

SDATA_IN

8

O

AC-Link Serial Data Input. AD1881A Output Stream.

SYNC

10

I

AC-Link Frame Sample Sync 48 kHz Fixed Rate.

RESET

11

I

AC-Link Reset. AD1881A Master H/W Reset.

Miscellaneous Connections

Pin Name

LQFP

I/O

Description

CS0

45

I

Chip Select 0.

CS1

46

I

Chip Select 1.

EAPD

47

O

External Amp Power-Down Control Signal, Default LO, Active HI

MODE

48

I

MODE Select.

Analog I/O

These signals connect the AD1881A component to analog sources and sinks, including microphones and speakers.

Pin Name

LQFP

I/O

Description

PC_BEEP

12

I

PC Beep. PC Speaker Beep Passthrough.

PHONE_IN

13

I

Phone. From Telephony Subsystem Speakerphone or Handset.

AUX_L

14

I

Auxiliary Input Left Channel.

AUX_R

15

I

Auxiliary Input Right Channel.

VIDEO_L

16

I

Video Audio Left Channel.

VIDEO_R

17

I

Video Audio Right Channel.

CD_L

18

I

CD Audio Left Channel.

CD_GND_REF

19

I

CD Audio Analog Ground Reference for Pseudo-Differential CD Input.

CD_ R

20

I

CD Audio Right Channel.

MIC1

21

I

Microphone 1. Desktop Microphone Input.

MIC2

22

I

Microphone 2. Second Microphone Input.

LINE_IN_L

23

I

Line In Left Channel.

LINE_IN_R

24

I

Line In Right Channel.

LINE_OUT_L

35

O

Line Out Left Channel.

LINE_OUT_R

36

O

Line Out Right Channel.

MONO_OUT

37

O

Monaural Output to Telephony Subsystem Speakerphone.

LNLVL_OUT_L

39

O

Line-Level Output Left Channel.

LNLVL_OUT_R

41

O

Line-Level Output Right Channel.

Filter/Reference

These signals are connected to resistors, capacitors, or specific voltages.

Pin Name

LQFP

I/O

Description

VREF

27

O

Voltage Reference Filter.

VREFOUT

28

O

Voltage Reference Output 5 mA Drive (Intended for MIC Bias).

AFILT1

29

O

Antialiasing Filter Capacitor—ADC Right Channel.

AFILT2

30

O

Antialiasing Filter Capacitor—ADC Left Channel.

FILT_R

31

O

AC-Coupling Filter Capacitor—ADC Right Channel.

FILT_L

32

O

AC-Coupling Filter Capacitor—ADC Left Channel.

RX3D

33

O

3D PHAT Stereo Enhancement—Capacitor.

CX3D

34

I

3D PHAT Stereo Enhancement—Capacitor.