L3235N ,HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONSfeatures ofpedances are externally programmable. Thethe broths function:L3234/L3235N kit is designe ..
L3235N. ,HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONSABSOLUTE MAXIMUM RATINGSSymbol Parameter Value UnitV100 Positive Power Supply Voltage +120 VV 5V Po ..
L3240 ,ELETRONIC TWO-TONE RINGERL3240ELETRONIC TWO-TONE RINGER. LOW CURRENT CONSUMPTION, IN ORDERTO ALLOW THE PARALLEL OPERATION OF ..
L3240D1 ,ELETRONIC TWO-TONE RINGERELECTRICAL CHARACTERISTICSo(T =25 C; V = applied between pins 7-2 ;otherwise specified)amb SSymbol ..
L3281AB ,LOW VOLTAGE TELEPHONE SPEECH CIRCUITSL3281LOW VOLTAGE TELEPHONE SPEECH CIRCUITSPRELIMINARY DATAOPERATION DOWN TO 1.6V / 6.5mADTMF & BEEP ..
L3845 ,TRUNK INTERFACEL3845®TRUNK INTERFACEON CHIP POLARITY GUARDMEETS DC LINE CHARACTERISTICS OFEITHER CCITT AND EIA RS ..
LB1876 ,Three-Phase Brushless Motor Driver for Polygon Mirror MotorsOrdering number : ENN6201AMonolithic Digital ICLB1876Three-Phase Brushless Motor Driver for Polygon ..
LB1877 ,Brushless Motor Driver with Speed Control for Portable Cassette RecordersElectrical Characteristics at Ta = 25
L3235N-L3235N.
HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONS
December 2001
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
DESCRIPTIONThe 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.
L3234
L3235NHIGHLY INTEGRATED SLIC KIT TARGETED TO PABX
AND KEY SYSTEM APPLICATIONS
1/25
ABS TYPICAL LINE CARD APPLICATION
L3234 - L3235N
DESCRIPTIONThe L3234 is a monolithic integrated circuit which
is part of a kit of solid state devices for the sub-
scriber line interface. The L3234 sends a ringing
signal into a two wires analog telephone line in
balanced mode. The AC ringing signal amplitude
is up to 60Vrms, and for that purpose a positive
supply voltage of +100V shall be available on the
subscriber card.
The L3234 receives a low amplitude ringing sig-
nal (950mVrms) and provide the voltage/current
amplification (60Vrms/70mA) when the enable in-
put is active (CS > 2V). In disable mode (CS <
0.8V) the power consumption of the chip is very
low (<14mW).
The circuit is designed with a high voltage bipolar
technology (VCEO > 140V / VCBO > 250V).
The package is a moulded plastic power package
(Heptawatt) suitable also for surface mounting.
BLOCK DIAGRAM
L3234 - L3235N
PIN CONNECTION (Top view)
ABSOLUTE MAXIMUM RATINGS
OPERATING RANGE
Note: Operating ranges define those limits between which the functionality of the device is guaranteed.
THERMAL DATA
PIN DESCRIPTION
L3234 - L3235N
Figure 1: L3234/L3235N Circuit ConfigurationWhen the ringing function is selected by the sub-
scriber card, a low level signal is continuously ap-
plied to pin 1 through a de coupling capacitor. Then
the logical ring drive signal CS provided by L3235N
is applied to pin 2 with a cadenced mode.
The ringing cycles are synchronised by the L3234
in such a way that the ringing starts and stops al-
ways when the analog input signal crosses zero.
When the ringing injection is enabled (CS = "1"),
an AC ringing signal is injected in a balanced
mode into the telephone line.
When the ringing injection is disabled (CS = "0"),
the output voltage on OUT2 raises to the high
power supply, whereas on OUT1, it falls down to
ground.
The L3234 has a low output impedance when
sending the signal, and high output impedance
when the ringing signal is disabled
In fig. 2 the dynamic features of L3234 are
shown.
OPERATION DESCRIPTIONThe Fig. 1 show the simplified circuit configuration
of the L3234 Solid State Ringing injector when
used with the L3235N Line Feeder.
EXTERNAL COMPONENTS LISTIn the following table are shown the recommended external components values for L3234.
L3234 - L3235N5/25
