TM
Document ID# 081123
Date:
Jun 1, 2006
Rev:
D
Version: 1
Distribution:
Public Document
Le75282
Dual Intelligent Line Card 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
device protection
5-V 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 per channel
RELATED LITERATURE
081065 Le79228 Quad ISLACTM Device Data Sheet
081190 Le792288 Octal ISLACTM Device Data Sheet
081143 Le79232 Dual ISLICTM Device Data Sheet
081144 Le79252 Dual ISLICTM Device Data Sheet
080923 Le792x2/Le79228 Chip Set User's Guide
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
Le75282BBVC
44-pin TQFP (Green)
Tray
DESCRIPTION
The Le75282 Dual Intelligent Line Card Access Switch (LCAS)
device is a monolithic solid-state device that provides the
switching functionality of four 2 Form C relays in one
economical small package.
The Le75282 Dual LCAS device is designed to provide power
ringing access to a telephone loop 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 additional pair of solid-state contacts provides access to the
telephone loop for line test access or message waiting in the
PBX application.
BLOCK DIAGRAM
FGND1
ASLIC1
ALINE1
ARINGING1
VDD
P1'-P3'
ATEST1
DGND
VBH
BSLIC1
BLINE1
BRINGING1
TSD1
OFF1
BTEST1
LD1
Control
Logic
SW2
SW1
SW3
SW5
SW6
SW4
Battery
Monitor
CHANNEL 1
CHANNEL 2
CFG
2
Le75282 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 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Absolute Maximum Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Operating Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Environmental Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Electrical Ranges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Zero Cross Current Turn Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Switching Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Loss of Battery Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Impulse Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Integrated SLIC Device Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Diode Bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Current Limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Temperature Shutdown Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
External Secondary Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Test Switch Protection Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Typical Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Physical Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
44-Pin TQFP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Revision A1 to B1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Revision B1 to C1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Revision C1 to D1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Le75282 VE750 Series Data Sheet
3
PRODUCT DESCRIPTION
The Le75282 Dual LCAS device has six operating states:
Idle/Talk
--
Line break switches closed, ringing and test access switches open.
Ringing
--
Ringing access switches closed, line break and test access switches open.
Test
--
Test access switches closed, line break and ringing access switches open.
Test/Monitor
--
Test access and line break switches closed, ringing access switches open.
Test Ringing
--
Test and ringing access switches closed, line break switches open.
All Off
--
Line break and ringing and test access switches open.
Control is provided by an Intelligent Subscriber Line Audio-processing Circuit (ISLAC), such as the Le79228 codec, or any
microcontroller. See
Applications, on page 14
for proper connection of the control bus (P-bus).
The Le75282 Dual LCAS device 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 > 320 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 Le75282 Dual LCAS device is a diode bridge, current-limiting circuitry, and a thermal shutdown mechanism
to provide protection to the SLIC device and subsequent circuitry during fault conditions. Positive faults are directed to ground
and negative faults to battery. In either polarity, faults are reduced by the built-in current-limit and/or thermal shutdown
mechanisms.
To protect the Le75282 Dual LCAS device from an overvoltage fault condition, use of a secondary protector is required. The
secondary protector must limit the voltage seen at the A (Tip)/B (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 Le75282 device will meet all relevant ITU-T,
LSSGR, FCC, or UL protection requirements.
The Le75282 Dual LCAS device provides extremely low idle and active power dissipation and allows use with virtually any range
of battery voltage. This makes the Le75282 Dual LCAS device especially appropriate for remote power applications such as
DAML or FOC/FITL or other Bellcore TA 909 applications where power dissipation is particularly critical.
Battery voltage is monitored by the control circuitry and used as a reference for the integrated protection circuit. The Le75282
device will enter an All Off state upon loss of battery.
During ringing, to turn on and maintain the ON state, the ringing access switch will draw a nominal 2 mA from the ring generator.
The Le75282 Dual LCAS device is packaged in a 44-pin TQFP package.
4
Le75282 VE750 Series Data Sheet
CONNECTION DIAGRAM
Pin Descriptions
CH1
CH2
Pin Name
Description
CH1
CH2
Pin Name
Description
27
7
FGND
x
Fault ground.
8, 26
VBH
High-battery voltage. Used as a
reference for protection circuit.
21
13
ASLIC
x
Connect to A lead on SLIC side.
22
12
BSLIC
x
Connect to B lead on SLIC side.
36
42
ALINE
x
Connect to A lead on line side.
34
44
BLINE
x
Connect to B lead on line side.
38
40
ARINGING
x
Connect to return ground of ringing
generator.
30
4
BRINGING
x
Connect to ringing generator.
37
41
ATEST
x
A lead test access.
33
1
BTEST
x
B lead test access.
9, 25
VDD
5 V supply.
17
18
LDx
Data latch channel control, active low.
28
6
TSD
x
Temperature shutdown flags. Read V
DD
potential when device is in its
operational mode and 0 V when device
is in the thermal shutdown mode.
14
P1'
Logic level input switch control.
Connect to P-bus. See
Applications, on
page 14
for proper connection.
11, 23
DGND
Digital ground.
15
P2'
Logic level input switch control.
Connect to P-bus. See
Applications, on
page 14
for proper connection.
19
20
OFFx*
All Off logic level input switch control. A
pull-down device is included, setting All
Off as the power-up default state. These
pins can also be used as a device reset.
If these pins are not to be used, they
must be tied to VDD.
16
P3'
Logic level input switch control.
Connect to P-bus. See
Applications, on
page 14
for proper connection.
2, 3, 5, 10, 29,
31, 32, 35, 39,
43
NC
No Connect. This pin is not internally
connected.
24
CFG
Operating states configuration. Tie to
DGND to select operating states as
defined in
Table 9
. Tie to VDD for
operating states as defined in
Table 10
.
Notes:
"x" denotes channel number.
* Internal pull down on this node.
23
24
25
26
27
28
29
30
31
32
33
NC
NC
BTEST1
BRINGING1
NC
TSD1
FGND1
VBH
VDD
CFG
DGND
12
18
17
16
15
14
13
19 20 21 22
44
38
39
40
41
42
43
37 36 35 34
44-pin TQFP
11
10
9
8
7
6
5
4
3
2
1
ALINE2
NC
BLINE2
ARINGING2
NC
ARINGING1
ATEST1
ALINE1
NC
BLINE1
ATEST2
P1'
ASLIC2
BSLIC2
P2'
LD1
LD2
OFF1
OFF2
ASLIC1
BSLIC1
P3'
NC
NC
BTEST2
BRINGING2
NC
TSD2
FGND2
VDD
NC
DGND
VBH
Le75282 VE750 Series Data Sheet
5
ABSOLUTE MAXIMUM RATING
Stresses above those listed under Absolute Maximum Ratings can cause permanent device failure. Functionality at or above
these limits is not implied. Exposure to absolute maximum ratings for extended periods can 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
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
--
330
V
ESD Immunity (Human Body Model)
JESD22 Class 1C compliant
Ambient Temperature
0 to 70C Commercial
40 to +85 C extended temperature
Ambient Relative Humidity
15 to 85%
V
DD
+4.75 V to +5.25 V
V
BH
19 V to 72 V
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