Si3220/25
Symbol
Input/
Output
Description
Pin Number(s)
Si3220 Si3225
9
9
IREF
I
I
IREF Current Reference.
Connects to an external resistor to provide a highly-accurate
reference current. Return path for IREF resistor should be
routed to QGND pin.
17, 64
17, 64
STIPDCb,
STIPDCa
TIP Sense.
Analog current input senses dc voltage on TIP side of sub-
scriber loop.
18, 63
19, 62
18, 63 STIPACb, STI-
PACa
I
I
TIP Transmit Input.
Analog input senses ac voltage on TIP side of subscriber loop.
19, 62
20, 61
21, 60
22, 59
23, 58
SRINGACb,
SRINGACa
RING Transmit Input.
Analog input senses ac voltage on RING side of subscriber
loop.
20, 61
21, 60
22, 59
23, 58
SRINGDCb,
SRINGDCa
I
RING Sense.
Analog current input senses dc voltage on RING side of sub-
scriber loop.
ITIPNb,
ITIPNa
O
O
O
Negative TIP Current Control.
Analog current output provides dc current return path to V
from TIP side of the loop.
BAT
BAT
IRINGNb,
IRINGNa
Negative RING Current Control.
Analog current output provides dc current return path to V
from RING side of the loop.
ITIPPb,
ITIPPa
Positive TIP Current Control.
Analog current output drives dc current onto TIP side of sub-
scriber loop in normal polarity. Also modulates ac current onto
TIP side of loop.
24, 37,
42, 57
24, 37,
42, 57
V
V
,V
,
Supply Voltage.
Power supply for internal analog and digital circuitry. Connect
DD2 DD3
,V
DD4 DD1
all V pins to the same supply and decouple to adjacent GND
DD
pin as close to the pins as possible.
25, 38,
41, 56
25, 38,
41, 56
GND2,GND3,
GND4,GND1
Ground.
Ground connection for internal analog and digital circuitry.
Connect all pins to low-impedance ground plane.
26, 55
26, 55
IRINGPb,
IRINGPa
O
Positive RING Current Control.
Analog current output drives dc current onto RING side of sub-
scriber loop in reverse polarity. Also modulates ac current onto
RING side of loop.
27,54
27,54
THERMb,
THERMa
I
Temperature Sensor.
Senses Internal temperature of Si3200. Connect to THERM pin
of Si3200 or to V when using discrete linefeed circuit.
DD
29, 51
29, 51
TRD1b,
TRD1a
O
Test Relay Driver Output.
Drives test relays for connecting loop test equipment.
Rev. 1.2
101
SILICON [ SILICON ]
