L3234 Datasheet, PDF (1/26 Pages) STMicroelectronics – HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONS

L3234
L3235
HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX
AND KEY SYSTEM APPLICATIONS
HIGHLY INTEGRATED SUBSCRIBER LINE
INTERFACE KIT FOR PABX AND KEY SYS-
TEM APPLICATIONS
IMPLEMENTS ALL KEY ELEMENTS OF THE
BORSCHT FUNCTION
INTEGRATED ZERO CROSSING BALANCED
RINGING INJECTION ELIMINATES EXTER-
NAL RELAY AND CENTRALISED RINGING
GENERATOR
ZERO NOISE INJECTED ON ADJACENT
LINES DURING RINGING SEQUENCE
LOW POWER IN STANDBY AND ACTIVE
MODES
BATTERY FEED WITH PROGRAMMABLE
LIMITING CURRENT
PARALLEL LATCHED DIGITAL INTERFACE
SIGNALLING FUNCTIONS (OFF HOOK,
GND-KEY)
LOW NUMBER OF EXTERNAL COMPO-
NENTS
INTEGRATED THERMAL PROTECTION
INTEGRATED OVER CURRENT PROTEC-
TION
0°C TO 70°C: L3234/L3235
-40°C TO 85°C: L3234T/L3235T
HEPTAWATT
ORDERING NUMBER: L3234
PLCC28
ORDERING NUMBER: L3235
DESCRIPTION
The L3234/L3235 is a highly integrated SLIC KIT
targeted to PABX and key system applications
The kit integrates the majority of functions re-
quired to interface a telephone line. The
L3234/L3235 implements the main features of the
broths function:
- Battery Feed (Balanced Mode)
- Ringing Injection
- Signalling Detection
- Hybrid Function
The Kit comprises 2 devices, the L3234 ringing
injector fabricated in Bipolar in 140V Technology.
Its function is to amplify and inject in balanced
mode with zero crossing the ringing signal. The
device requires an external positive supply of
100V and a low level sinusoid of approx.
950mVrms. The L3235 Line Feeder is integrated
in 60V Bipolar Technology. The L3235 provides
battery feed to the line with programmable current
limitation. The two to four wire voice frequency
signal conversion is implemented by the L3235
and line terminating and balance impedances are
externally programmable. The L3234/L3235 kit is
designed for low power dissipation. In a short
loop condition the extra power is dissipated on an
external transistor. The Kit is controlled by five
wire parallel bus and interfaces easily to all first
and programmable second generation COMBOS.
(see figg. 1 and 2)
Janauary 1995
1/26
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.