Si3220/25 Si3200/02
102
Rev. 1.3
Not
Recommended
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99
IREF
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
STIPDCb,
STIPDCa
I
TIP Sense.
Analog current input senses dc voltage on TIP side of sub-
scriber loop.
18, 63
STIPACb, STI-
PACa
I
TIP Transmit Input.
Analog input senses ac voltage on TIP side of subscriber loop.
19, 62
SRINGACb,
SRINGACa
I
RING Transmit Input.
Analog input senses ac voltage on RING side of subscriber
loop.
20, 61
SRINGDCb,
SRINGDCa
I
RING Sense.
Analog current input senses dc voltage on RING side of sub-
scriber loop.
21, 60
ITIPNb,
ITIPNa
O
Negative TIP Current Control.
Analog current output provides dc current return path to VBAT
from TIP side of the loop.
22, 59
IRINGNb,
IRINGNa
O
Negative RING Current Control.
Analog current output provides dc current return path to VBAT
from RING side of the loop.
23, 58
ITIPPb,
ITIPPa
O
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
VDD2,VDD3,
VDD4,VDD1
Supply Voltage.
Power supply for internal analog and digital circuitry. Connect
all VDD pins to the same supply and decouple to adjacent GND
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
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
THERMb,
THERMa
I
Temperature Sensor.
Senses Internal temperature of Si3200/2. Connect to THERM
pin of Si3200/2 or to VDD when using discrete linefeed circuit.
29, 51
TRD1b,
TRD1a
O
Test Relay Driver Output.
Drives test relays for connecting loop test equipment.
Pin Number(s)
Symbol
Input/
Output
Description
Si3220
Si3225