Document ID# 081105
Date:
May 31, 2006
Rev:
E
Version: 1
Distribution:
Public Document
TM
Le75181
Ringing Access Switch
VE750 Series
APPLICATIONS
Central office
DLC
PBX
DAML
HFC/FITL
FEATURES
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 drive circuitry
Only one external protector required
TTL logic control compatible
Default power up state
RELATED LITERATURE
081123 Le75282 Dual Intelligent Line Card Access
Switch Data Sheet
081126 Le75183 Line Card Access Switch Data Sheet
080754 Le58QL061/063 QLSLAC
Data Sheet
080676 Le5711 Dual SLIC Data Sheet
081047 Le5712 Dual SLIC Data Sheet
ORDERING INFORMATION
1.
The green package meets RoHS Directive 2002/95/EC of the
European Council to minimize the environmental impact of
electrical equipment.
2.
For delivery using a tape and reel packing system, add a "T" suffix
to the OPN (Ordering Part Number) when placing an order.
Device
Package Type
1
Packing
2
LE75181ABSC
16-Pin SOIC, GULL (Green)
Tube
LE75181BBSC
LE75181CBSC
DESCRIPTION
The VoiceEdgeTM family VE750 series of Line Card Access
Switches (LCAS) is a family of monolithic solid-state switches
that is designed to provide both power ringing access and test
access on the analog line card. These devices, while not a pin-
for-pin replacement for the traditional electromechanical relay
(EMR) solution, provide the equivalent switching functionality.
The VE750 series LCAS is meant as a solid-state alternative to
the EMRs.
The Le75181A/B device is pin-for-pin compatible with
Legerity's L7581A/B device, and the Le75181C device is pin-
for-pin compatible with Legerity's L8581A device.
Legerity also offers a range of compatible SLIC devices and
codec/filters that can be used with the VE750 series LCAS for
complete line card solutions that can be used worldwide in
analog line card applications.
BLOCK DIAGRAM
SCR
& Trip
Circuit
Temperature
Shutdown
SW4
SW3
VBAT
RBAT
RLINE
RRINGING
LATCH
INPUT
DGND
FGND
TBAT
TLINE
TRINGING
VDD
TSD
Le75181A/C
SW1
SW2
Temperature Shutdown
SW4
SW3
VBAT
RBAT
RLINE
RRINGING
LATCH
INPUT
DGND
FGND
TBAT
TLINE
TRINGING
VDD
TSD
Le75181B
SW1
SW2
2
Le75181 VE750 Series Data Sheet
TABLE OF CONTENTS
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Related literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Environmental Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Electrical Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Summary of Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Supply Currents and Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Device Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Zero Cross Current Turn Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Switching Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Loss of Battery Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Impulse Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Integrated SLIC Device Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Typical Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Physical Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
16-Pin, Plastic SOIC (GULL) (ASC/BSC/CSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Revision history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Revision A1 to B1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Revision B1 to C1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Revision C1 to D1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Revision D1 to E1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Le75181 VE750 Series Data Sheet
3
PRODUCT DESCRIPTION
The Le75181 Ringing Access Switch is a monolithic solid-state device that provides the switching functionality of a two-form C
switch.
The Le75181 is designed to provide power ringing access 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. The Le75181 has three
states: the idle talk state (line break switches closed, ringing access switches open), power ringing state (line break switches
open, ringing access switches closed), and all OFF state.
The Le75181 offers break-before-make or make-before-break switching, with simple logic level input control. Because of the
solid-state construction, voltage transients generated when switching into an inductive ringing load 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 protection,
to prevent breakdown in the presence of a transient fault condition (i.e., passing the transient on to the ringing generator).
Incorporated into the Le75181A and Le75181C is a diode bridge/SCR clamping circuit, current-limiting circuitry, and a thermal
shutdown mechanism to provide protection to the SLIC device and subsequent circuitry during fault conditions (see block
diagram). Positive and negative lightning is reduced by the current-limiting circuitry and steered to ground via diodes and the
integrated SCR. Power cross is also reduced by the current-limiting and thermal shutdown circuits.
The Le75181B version provides only an integrated diode bridge along with current limiting and thermal shutdown, as shown in
the block diagram. This will cause positive faults to be directed to ground and negative faults to battery. In either polarity, faults
are reduced by the current-limit and/or thermal shutdown mechanisms.
The default power up state is in Idle/Talk state unless otherwise being overwritten by external controls.
To protect the Le75181 from an overvoltage fault condition, use of a secondary protector is required. The secondary protector
must limit the voltage seen at the tip/ring terminals to prevent the breakdown voltage of the switches from being exceeded. To
minimize stress on the solid-state contacts, use of a foldback- or crowbar- type secondary protector is recommended. With proper
choice of secondary protection, a line card using the Le75181 will meet all relevant ITU-T, LSSGR, FCC, or UL* protection
requirements.
The Le75181 operates off of a 5-V supply only. This gives the device extremely low idle and active power dissipation and allows
use with virtually any range of battery voltage. This makes the Le75181 especially appropriate for remote power applications
such as DAML or FOC/FITL or other Bellcore TA 909 applications where power dissipation is particularly critical.
A battery voltage is also used by the Le75181, only as a reference for the integrated protection circuit. The Le75181 will enter an
all OFF state upon loss of battery.
During power ringing, to turn on and maintain the ON state, the ring access switch will draw a nominal 2 mA from the ring
generator.
The Le75181ASC/BSC/CSC device is packaged in a 16-pin, plastic SOIC (GULL) package.
4
Le75181 VE750 Series Data Sheet
CONNECTION DIAGRAMS
Figure 1. 16-Pin SOIC
Pin Descriptions
Pin Name
Type
Description
D
GND
Ground
Digital ground.
F
GND
Ground
Fault ground.
INPUT
Input
Logic level input switch control. Internally 75 k
typical pull down.
LATCH
Input
Data latch control, active-high, transparent low. Internally 75 k
typical pull down.
NC
--
No connection.
R
BAT
Input/Output
Connect to RING on SLIC side.
R
LINE
Input/Output
Connect to RING on line side.
R
RINGING
Input/Output
Connect to ringing generator.
T
BAT
Input/Output
Connect to TIP on SLIC side.
T
LINE
Input/Output
Connect to TIP on line side.
T
RINGING
Input/Output
Connect to return ground for ringing generator.
T
SD
Input/Output
Temperature shutdown pin. Can be used as a logic level input or output. See table 8, truth
table, on page 15, and the Switching Behavior section of this data sheet for input pin
description. As an output, will read HIGH when device is in its operational mode and
LOW
in the thermal shutdown mode. In the Le75181, the thermal shutdown mechanism cannot
be disabled.
V
BAT
Input
Battery voltage. Used as a reference for protection circuit.
V
DD
Power
5-V supply.
16-Pin SOIC
FGND
1
TBAT
2
TLINE
3
NC
4
NC
5
TRINGING
6
VDD
7
TSD
8
9
10
11
12
13
14
15
16
VBAT
RBAT
RLINE
NC
RRINGING
LATCH
INPUT
DGND
Le75181 VE750 Series Data Sheet
5
ABSOLUTE MAXIMUM RATINGS
Stresses above those listed under Absolute Maximum Ratings may cause permanent device failure. Functionality at or above
these limits is not implied. Exposure to absolute maximum ratings for extended periods may affect device reliability.
Package Assembly
Green package devices are assembled with enhanced, environmental compatible lead-free, halogen-free, and antimony-free
materials. The leads possess a matte-tin plating which is compatible with conventional board assembly processes or newer lead-
free board assembly processes. The peak soldering temperature should not exceed 245C during printed circuit board assembly.
Refer to IPC/JEDEC J-Std-020B Table 5-2 for the recommended solder reflow temperature profile.
OPERATING RANGES
Environmental Ranges
Legerity guarantees the performance of this device over commercial (0 to 70 C) and industrial (-40 to 85C) temperature ranges
by conducting electrical characterization over each range and by conducting a production test with single insertion coupled to
periodic sampling. These characterization and test procedures comply with section 4.6.2 of Bellcore GR-357-CORE Component
Reliability Assurance Requirements for Telecommunications Equipment.
Electrical Ranges
*V
BAT
is used only as a reference for internal protection circuitry. If V
BAT
rises above 10 V, the device will enter an all OFF state and remain in
this state until the battery voltage drops below 15 V.
Parameter
Min
Max
Unit
Operating Temperature Range
40
110
C
Storage Temperature Range
40
150
C
Relative Humidity Range
5
95
%
Pin Soldering Temperature (t=10 s max)
--
260
C
5-V Power Supply
-0.3
7
V
Battery Supply
--
85
V
Logic Input Voltage
-0.3
V
DD
+0.3
V
Input-to-output Isolation
--
330
V
Pole-to-pole Isolation (All except SW 4)
--
330
V
Pole-to-pole Isolation (Ringing Access Switch, SW4)
--
480
V
ESD Immunity (Human Body Model)
JESD22 Class 1C compliant
Ambient Temperature
-40 to 85C
Supply
Min
Typ
Max
Unit
V
DD
4.5
5
5.5
V
V
BAT
*
19 --
72
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