Data Sheet AS2523, AS2524, AS2524B

Revision 1.12, Preliminary

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

9STB

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

8M1

Differential input for the handset microphone (electret)

6M2

Differential input for the handset microphone (electret)

7M3

Differential input for the handsfree microphone (electret)

5M4

Differential input for the handsfree microphone (electret)

17

RO

Output for driving a dynamic earpiece with an impedance from 150

Ω to 300Ω