Data Sheet AS2523, AS2524, AS2524B

Revision 1.13

Page 2 of 19

Pin description

Pin #

Symbol

Function

15

LS

Analog input for sensing the line current

12

LI

Analog input used for power extraction and line current sensing

13

RI

Analog input for ac-separated receive signal

9

STB

Analog input for side tone cancellation network

10

CS

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

synthesizing AC- and DC-impedance, modulation of line voltage and shorting the line during

make periods of pulse dialing

16

CI

Analog input pin for the capacitor to program a complex impedance

14

SS

N-channel open drain output to control the external high power source transistor for supplying

(Vpp) the loudspeaker amplifier in off-hook loudspeaking/handsfree mode

11

VSS

Negative Analog Power Supply

18

VDD

Positive Analog Power Supply

19

AGND

Special ground for the internal amplifiers

8

M1

Differential input for the handset microphone (electret)

6

M2

Differential input for the handset microphone (electret)

7

M3

Differential input for the handsfree microphone (electret)

5

M4

Differential input for the handsfree microphone (electret)

17

RO

Output for driving a dynamic earpiece with an impedance from 150Ω to 300Ω