REV. M

Page 2

September 1998

AS3502

Pinout Diagramme

1

2

3

4

5

6

7

8

9

10

11

12

13

14

CAP

MIC1+

MIC1-

MIC2-

MIC2+

N.C.

POR

SCL

SDI

SDO

RXD

SPK-

SPK+

EP-

EP+

TRO-

TRO+

GNDD

MCLK

CS

SCLK

TXD

TXS

RXS

28

27

26

25

24

23

22

21

20

19

18

17

16

15

28 Pin SOIC

A S3502

1

3

6

12

14

16

45

42

40

38

34

MIC2-

MIC2+

PO R

CS

EP+

TRO -

TRO +

G NDD

MCLK

64 pin TQ FP

Pin Description

Pin #

Name

Type

Function

1

AVDD

SI

Analogue Positive Supply Voltage Input

2

CAP

AO

Filter Capacitor Output

This pin requires to be connected to an external blocking capacitor of app. 47µF

and is internally connected to the potential divider of the analogue ground genera-

tion circuit.

3

4

MIC1-

MIC1+

AI

AI

Differential Microphone 1 Inputs

These two pins are differential inputs to the analogue input multiplexer of the gain

programmable microphone amplifier with an input impedance of approx. 60 k

Ω.

5

6

MIC2-

MIC2+

AI

AI

Differential Microphone 2 Inputs

These two pins are differential inputs to the analogue input multiplexer of the gain

programmable microphone amplifier with an input impedance of approx. 60 k

Ω.

7

N.C.

8

VREF

AO

Microphone Reference Voltage Output

This pin provides a stabilized reference voltage for an electret microphone of

approx. 2V.

9

DVDD

SI

Digital Positive Supply Voltage Input