L3234 STMicroelectronics, L3234 Datasheet - Page 11

• Manufacturer Part Number: L3234
• Description: HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONS
• Manufacturer: STMicroelectronics

DESCRIPTION
Circuit description
The L3235 Subscriber Line Interface Circuit
(SLIC) is a bipolar integrated circuit in 60V tech-
nology optimized for PABX application.
The L3235 supplies a line feed voltage with a cur-
rent limitation which can be modified by an exter-
nal resistor (RLIM).
The SLIC incorporates loop currents, ground key
detection functions with an externally programma-
ble constant time.
The two to four wires and four to two wires voice
frequency signal conversion is performed by the
L3235 and the line terminating and the balancing
impedances are externally programmable.
The device integrates an automatic power limita-
tion circuit. In short loop condition the extra power
is dissipated on one external transistor (Text).
This aproach allows to assembly the L3235 in a
low cost standard plastic PLCC28 package.
The chip is protected by thermal protection at
Tj = 150 C.
The SLIC is able to give a power up command for
Combo in off hook condition and an enable logic
for solid state ringing injector L3234.
The L3235 package is 28 pin plastic PLCC.
The L3235 has been designed to operate
togheter
BORSHT function without any electromechanical
ringing relay (see the application circuit fig. 16).
ABSOLUTE MAXIMUM RATINGS
OPERATING RANGE
Note: Operating ranges define those limits between which the functionality of the device is guaranteed.
Symbol
Symbol
V
V
V
V
T
V
V
T
BAT
T
BAT
T
CC
SS
stg
CC
SS
op
j
j
with
Battery Voltage
Positive Supply Voltage
Negative Supply Voltage
Max. Junction Temperature
Storage Temperature
Battery Voltage
Positive Supply Voltage
Negative Supply Voltage
Operating Temperature for L3235
Max Junction Operating Temperature
Subscriber Line Interface Circuit
L3234
performing
Parameter
Parameter
L3235T
complete
L3235
PIN CONNECTION
-5.25
Min.
4.75
-52
-40
0
PLCC28
-55 to +150
Value
-5.5
150
-54
5.5
-4.75
Max.
5.25
130
-24
70
85
L3234 - L3235
Unit
V
V
V
Unit
C
C
C
V
V
V
11/26
C
C