Preliminary Data Sheet

AS2504

2/12

August 1998

Pin description

Pin #

Symbol

Function

7LS

Input for sensing the line current

5LI

Input used for power extraction and line current sensing

6RI

Input for ac-separated receive signal

13

STB

Input for side tone cancellation network

3CS

N-channel open drain output to control the external high power shunt transistor

for synthesising AC- and DC-impedance, modulation of line voltage and shorting

the line during make periods of pulse dialling

14

CI

Input pin for the capacitor to program a complex impedance

25

MASK

MASK

Input pin to set circuit into power down mode during e.g. LD-dialling. During

MASK=HIGH, CS-pin is internally shorted to ground.

26

LLC

45mA-75mA

—> VDD

20mA-50mA

—> AGND

None

—> VSS

11

VDD

4VSS

Negative Power Supply

12

AGND

Special ground for the internal amplifiers

2M1

Differential input for the microphone (electret)

1M2

Differential input for the microphone (electret)

28

M3

Differential input for the microphone (electret)

27

M4

Differential input for the microphone (electret)

24

ATI1

Ω

23

ATI2

Ω