
December 2001
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/L3235N
-40
°
C TO 85
°
C: L3234T/L3235NT
DESCRIPTION
The L3234/L3235N is a highly integrated SLIC
KIT targeted to PABX and key system applica-
tions
The kit integrates the majority of functions re-
quired to interface a telephone line. The
L3234/L3235N 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 L3235N Line Feeder is inte-
grated in 60V Bipolar Technology. The L3235N
provides battery feed to the line with programma-
ble current limitation. The two to four wire voice
frequency signal conversion is implemented by
the L3235N and line terminating and balance im-
pedances are externally programmable. The
L3234/L3235N kit is designed for low power dissi-
pation. 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 the STLC5046 and STLC5048
CODECs. In Kit with STLC5048 (see fig 1) the
line impedance synthesis and echo canceling are
performed inside the CODEC.
HEPTAWATT
ORDERING NUMBER:
L3234
TQFP44
ORDERING NUMBER:
L3235N
L3234
L3235N
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