SA2532
PIN DESCRIPTION
Pin#
23
24
3
2
5
28
6
1
27
25
Symbol
M1
M2
RO1
RO2
A
GND
RI
STB
LS
LI
CS
Function
Microphone Inputs
Differential inputs for the microphone (electret).
Receiver Outputs
These are the outputs for driving a dynamic earpiece with an impedance
of 100 to 300Ω
Analog Ground
This is the analog ground for the amplifiers.
Receive Input
This is the input for the receive signal.
Side Tone Balance Input
This is the input for side tone cancellation.
Line Current Sense Input
This is the input for sensing the line current.
Line Input
This input is used for power extraction and line current sensing.
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.
Positive Voltage Supply
This is the supply pin for the circuit.
Negative Power Supply
Melody Output
Pulse Density Modulated output of the melody generator for tone ringer. At
high impedance when not active.
Frequency Comparator Input
This is a Schmitt trigger input for ring frequency discrimination. Disabled
during off-hook.
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.
Oscillator Input
Oscillator pin for Xtal or ceramic resonator (3.58 MHz).
Line Loss Compensation
Select pin for line loss compensation.
Repetition Rate
Select pin for repetition rate of melody.
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
Keyboard Rows
4
26
8
V
DD
V
SS
MO
21
FCI
10
HS/DP
11
9
12
22
OSC
LLC
RR
MODE
20
19
18
17
16
15
14
13
7
R1
R2
R3
R4
C1
C2
C3
C4
CI
Keyboard Columns
Complex Impedance Input
Input pin for the capacitor in the complex impedance
2/22
sames
SAMES [ SAMES ]
