Data Sheet AS2522B

Revision 3.4

Page 2 of 19

Pin description

Pin #

Symbol

Function

13

LS

Analog input for sensing the line current

10

LI

Analog input used for power extraction and line current sensing

11

RI

Analog input for ac-separated receive signal

7STB

Analog input for side tone cancellation network

8CS

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

14

CI

Analog input pin for the capacitor to program a complex impedance

12

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

9

VSS

Negative Analog Power Supply

18

VDD

Positive Analog Power Supply

19

AGND

Special ground for the internal amplifiers

6M1

Differential input for the handset microphone (electret)

4M2

Differential input for the handset microphone (electret)

5M3

Differential input for the handsfree microphone (electret)

3M4

Differential input for the handsfree microphone (electret)

17

RO

Output for driving a dynamic earpiece with an impedance from 150

Ω to 300Ω

31

OSC

Input for ceramic resonator 3.58MHz.