L8583D Line Card Access Switch
Features
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Small size/surface-mount packaging
Monolithic IC reliability
Low impulse noise
Make-before-break, break-before-make operation
Clean, bounce-free switching
Low, matched on-resistance
Built-in current limiting, thermal shutdown, and
SLIC protection
5 V only operation, very low power consumption
Battery monitor, all-off state upon loss of battery
No EMI
Latched logic level inputs, no driver circuitry
Only one external protector required
The L8583D has eight states: the idle talk state (line
break switches closed, all other switches open), the
power ringing state (ringing access switches closed,
all other switches open), loop access state (loop
access switches closed, all switches open), SLIC test
state (test in switches closed, all other switches
open), simultaneous loop and SLIC access state
(loop and test in switches closed, all others open),
ringing generator test state (ring test switches closed,
all others open), simultaneous test-out and ring-test
state (ring and test out switches closed), and an all-
off state. The L8583D is appropriate for central office,
access, digital loop carrier, and other
Telcordia Tech-
nologies™
TR-57 applications.
The L8583D offers break-before-make or make-
before-break switching, with simple logic-level input
control. Because of the solid-state construction, volt-
age transients generated when switching into an
inductive ringing lead during ring cadence or ring trip
are minimized, possibly eliminating the need for
external zero cross switching circuitry. State control is
via logic level inputs, so no additional driver circuitry
is required.
The line break switch is a linear switch that has
exceptionally low on-resistance and an excellent
on-resistance matching characteristic. The ringing
access switch has a breakdown voltage rating
>480 V which is sufficiently high, with proper protec-
tion, to prevent breakdown in the presence of a tran-
sient fault condition (i.e., passing the transient on to
the ringing generator).
The L8583D provides an integrated diode bridge
along with current limiting and thermal shutdown for
protection of the device itself and the subsequent
subscriber line integrated circuit (SLIC). For LCAS
protection, power cross is reduced by the current-
limiting and thermal shutdown circuits and lightning
reduced by the current-limit circuit. Residue faults are
shunted from the SLIC by the diode bridge.
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Applications
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Central office
DLC
PBX
DAML
HFC/FITL
Description
The Legerity L8583D line card access switch is a
monolithic solid-state device providing
the equivalent switching functionality of three 2-form
C switches. The L8583D is designed to provide
power ringing access, line test access (test out), and
SLIC test access (test in) to tip and ring in central
office, digital loop carrier, private branch exchange,
digitally added main line, and hybrid fiber coax/fiber-
in-the-loop analog line card applications. An addi-
tional pair of solid-state contacts are also available to
provide access for testing of the ringing generator.
Document ID#
080990
Rev:
A
Distribution:
Public
Date:
Version:
Oct 31, 2002
1
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
