PROTECTION PRODUCTS
PRELIMINARY
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www.semtech.com
PROTECTION PRODUCTS
LCDA12C-1 & LCDA15C-1
Low Capacitance TVS Diode Array
Description
Features
Circuit Diagram
Schematic & PIN Configuration
Revision 9/2000
The LCDAxxC-1 is a low capacitance transient voltage
suppressor (TVS) diode array. It is designed to protect
sensitive CMOS ICs from the damaging effects of ESD
and lightning. Each device will protect one line in
common (line-to-ground) mode or one line pair in
metallic (Line-to-line) mode. They are low capacitance
(< 15pF) making them suitable for use on high-speed
telecom and datacom interfaces without signal degra-
dation.
The configuration of the LCDAxxC-1 has been optimized
for easy layout on high density boards. The small SOT-
143 package minimizes required board space. These
devices will handle up to 20 Amps for an 8/20s
lightning impulse. The low inductance construction
minimizes voltage overshoot during high current
surges.
The LCDAxxC-1 may be used to protect ADSL inter-
faces, multi-protocol serial transceivers, portable
electronics, and wireless systems.
Applications
Mechanical Characteristics
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ADSL Interfaces
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RS-232, RS-422, V.90 Interfaces
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Multi-Protocol Serial Transceivers
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High-Speed Data Lines
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Portable Electronics
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WAN/LAN Equipment
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Wireless Systems
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ESD protection to IEC 61000-4-2, Level 4
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Lightning protection per IEC 61000-4-5
(20A, tp=8/20s)
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Configuration optimized for easy board layout
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Protects one line pair
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Low capacitance (<15pF) for high-speed interfaces
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Low clamping voltage
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Low leakage current
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Operating voltage: 12V & 15V
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Solid-state silicon-avalanche technology
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JEDEC SOT-143 package
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Molding compound flammability rating: UL 94V-0
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Marking : Marking code
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Packaging : Tape and Reel per EIA 481
SOT-143 (Top View)
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2000 Semtech Corp.
www.semtech.com
PROTECTION PRODUCTS
PROTECTION PRODUCTS
LCDA12C-1 & LCDA15C-1
Applications Information
Device Connection for Metallic Protection of High-
Speed Data Lines
The LCDAxxC-1 is designed to protect high-speed data
lines from transient over-voltages which result from
lightning and ESD. The device is designed to protect
one line in common mode (Line-to-Ground) or one line
pair in metallic (Line-to-Line) mode. For metallic mode
protection, the input of line 1 is connected at pin 1 and
the output is connected at pin 4. Likewise, the input
of line 2 is connected at pin 2 and the output is con-
nected at pin 3. For common mode protection, ground
either pins 1 & 4 or pins 2 & 3. The ground connection
should be made directly to the ground plane for best
results.
ADSL Protection
A typical ADSL protection circuit is shown in Figure
3. The LCDA12C-1 (or LCDA15C-1 for 15 volt drivers)
is connected from each line to ground on the IC side of
the line. They provide lightning and ESD protection for
the sensitive line driver IC.
1
2
3
4
Line
In
Line
In
Line
Out
Line
Out
Figure 1 - Connection for Differential Protection
(Line-to-Line)
1
2
3
4
Line
In
Line
Out
Figure 2 - Connection for Common Mode
Protection (Line-to-Ground)
Figure 3 - ADSL Protection Circuit
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