PROTECTION PRODUCTS
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PROTECTION PRODUCTS
SMDA05C-7 THRU SMDA24C-7
Bidirectional TVS Array
for Protection of Seven Lines
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Transient protection for data lines to
IEC 61000-4-2 (ESD) 15kV (air), 8kV (contact)
IEC 61000-4-4 (EFT) 40A (5/50ns)
IEC 61000-4-5 (Lightning) 12A (8/20s)
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Small SO-8 surface mount package
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Protects seven I/O lines
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Working voltages: 5V, 12V, 15V and 24V
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Low leakage current
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Low operating and clamping voltages
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Solid-state silicon avalanche technology
Description
Features
Schematic & PIN Configuration
Revision 9/2000
Applications
Mechanical Characteristics
The SMDAxxC-7 series of transient voltage suppres-
sors are designed to protect components which are
connected to data and transmission lines from voltage
surges caused by ESD (electrostatic discharge), EFT
(electrical fast transients), and lightning.
TVS diodes are characterized by their high surge
capability, low operating and clamping voltages, and
fast response time. This makes them ideal for use as
board level protection of sensitive semiconductor
components. The SMDAxxC-7 is designed to provide
transient suppression on multiple data lines and I/O
ports. The low profile SO-8 design allows the user to
protect up to seven data and I/O lines with one pack-
age.
The SMDAxxC-7 TVS diode array will meet the surge
requirements of IEC 61000-4-2 (Formerly IEC 801-2),
Level 4, Human Body Model for air and contact
discharge.
SO-8 (Top View)
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JEDEC SO-8 package
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Molding compound flammability rating: UL 94V-0
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Marking : Part number, date code, logo
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Packaging : Tube or Tape and Reel per EIA 481
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RS-232 & RS-422 Data Lines
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Microprocessor Based Equipment
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LAN/WAN Equipment
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Notebooks, Desktops, & Servers
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Instrumentation
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Peripherals
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Set Top Box
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Serial and Parallel Ports
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2000 Semtech Corp.
www.semtech.com
PROTECTION PRODUCTS
PROTECTION PRODUCTS
SMDA05C-7 THRU SMDA24C-7
Circuit Diagram
Connection Diagram
Device Connection for Protection of Seven Data Lines
The SMDAxxC-7 is designed to protect up to 7 data or
I/O lines. They are bidirectional devices and may be
used on lines where the signal polarities are above and
below ground.
The SMDAxxC-7 TVS arrays employ a monolithic struc-
ture. Therefore, the working voltage (V
RWM
) and break-
down voltage (V
BR
) specifications apply to the differen-
tial voltage between any two data line pins. For ex-
ample, the SMDA24C-7 is designed for a maximum
voltage excursion of +/-12V between any two data
lines.
The device is connected as follows:
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Pins 1, 2, 3, 4, 5, 6 and 7 are connected to the
lines that are to be protected. Pin 8 is connected
to ground. The ground connections should be
made directly to the ground plane for best results.
The path length is kept as short as possible to
reduce the effects of parasitic inductance in the
board traces.
Circuit Board Layout Recommendations for Suppres-
sion of ESD.
Good circuit board layout is critical for the suppression
of ESD induced transients. The following guidelines are
recommended:
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Place the TVS near the input terminals or connec-
tors to restrict transient coupling.
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Minimize the path length between the TVS and the
protected line.
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Minimize all conductive loops including power and
ground loops.
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The ESD transient return path to ground should be
kept as short as possible.
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Never run critical signals near board edges.
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Use ground planes whenever possible.
1
2
3
4
5
6
7
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DATA IN
DATA OUT
DATA IN
DATA OUT
Applications Information