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SA2532

sames

PIN DESCRIPTION

Pin#

Symbol

Function

23

M1

Microphone Inputs

24

M2

Differential inputs for the microphone (electret).

3

RO1

Receiver Outputs

2

RO2

These are the outputs for driving a dynamic earpiece with an impedance

of 100 to 300

Ω

5A

GND

Analog Ground

This is the analog ground for the amplifiers.

28

RI

Receive Input

This is the input for the receive signal.

6STB

Side Tone Balance Input

This is the input for side tone cancellation.

1LS

Line Current Sense Input

This is the input for sensing the line current.

27

LI

Line Input

This input is used for power extraction and line current sensing.

25

CS

Current Shunt Control Output

This N-channel open drain output controls the external high power shunt

transistor for the modulation of the line voltage and for shorting the line

during make period of pulse dialling.

4V

DD

Positive Voltage Supply

This is the supply pin for the circuit.

26

V

SS

Negative Power Supply

8MO

Melody Output

Pulse Density Modulated output of the melody generator for tone ringer. At

high impedance when not active.

21

FCI

Frequency Comparator Input

This is a Schmitt trigger input for ring frequency discrimination. Disabled

during off-hook.

10

HS/DP

Hook Switch Input and Dial Pulse Output

This is an I/O that is pulled high by the hook switch when off- hook. An open

drain pulls it low during break periods of pulse dialling and flash.

11

OSC

Oscillator Input

Oscillator pin for Xtal or ceramic resonator (3.58 MHz).

9

LLC

Line Loss Compensation

Select pin for line loss compensation.

12

RR

Repetition Rate

Select pin for repetition rate of melody.

22

MODE

Signalling Mode Select Input

Mode pin

Function

High

LD default mode, make/break = 33/66 ms

Open

MF only

Low

LD default mode, make/break = 40/60 ms

20

R1

Keyboard Rows

19

R2

18

R3

17

R4

16

C1

Keyboard Columns

15

C2

14

C3

13

C4

7CI

Complex Impedance Input

Input pin for the capacitor in the complex impedance