PROTECTION PRODUCTS
1www.semtech.com
PROTECTION PRODUCTS
SMDA05 through SMDA24
Unidirectional TVS Array
for Protection of Four Lines
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 (8/20µs)
Undirectional protection
Small SO-8 package
Protects four I/O lines
Working voltages: 5V, 12V, 15V and 24V
Low leakage current
Low operating and clamping voltages
Solid-state silicon avalanche technology
Description Features
Schematic & PIN Configuration
Revision 08/15/06
Applications
Mechanical Characteristics
The SMDAxx series of TVS arrays are designed to provide
undirectional protection for sensitive electronics from
damage or latch-up due to ESD, lightning, and other
voltage-induced transient events. Each device will
protect four data or I/O lines. They are available with
operating voltages of 5V, 12V, 15V and 24V.
TVS diodes are solid-state devices designed specifically
for transient suppression. They offer desirable charac-
teristics for board level protection including fast re-
sponse time, low operating and clamping voltage and no
device degradation. The low profile SO-8 package allows
the user to protect up to four independent lines with one
package. The SMDAxx series is suitable protection for
sensitive semiconductors components such as micropro-
cessors, ASICs, transceivers, transducers, and CMOS
memory.
The SMDAxx series devices may be used to meet the
ESD immunity requirements of IEC 61000-4-2, level 4 for
air and contact discharge.
SO-8 (Top View)
JEDEC SO-8 package
Molding compound flammability rating: UL 94V-0
Marking : Part number, date code, logo
Packaging : Tube or Tape and Reel per EIA 481
RS-232 data lines
Microprocessor based equipment
Notebooks, Desktops, and Servers
Instrumentation
LAN/WAN equipment
Peripherals
Serial and Parallel Ports
1
2
3
45
6
7
8
22005 Semtech Corp. www.semtech.com
PROTECTION PRODUCTS
PROTECTION PRODUCTS
SMDA05 through SMDA24
Absolute Maximum Rating
Electrical Characteristics (T=25oC)
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32005 Semtech Corp. www.semtech.com
PROTECTION PRODUCTS
SMDA05 through SMDA24
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Electrical Characteristics (Continued)
42005 Semtech Corp. www.semtech.com
PROTECTION PRODUCTS
PROTECTION PRODUCTS
SMDA05 through SMDA24
Typical Characteristics
Non-Repetitive Peak Pulse Power vs. Pulse Time Power Derating Curve
0
10
20
30
40
50
60
70
80
90
100
110
0 5 10 15 20 25 30
Time (µs)
Percent of IPP
e-t
td = IPP/2
W
ave
f
orm
Parameters:
tr = 8µs
td = 20µs
Pulse Waveform
ESD Pulse Waveform (IEC 61000-4-2)
0
10
20
30
40
50
60
70
80
90
100
110
0 25 50 75 100 125 150
Ambient Temperature - TA (oC)
% of Rated Power or I
PP
0.01
0.1
1
10
0.1 1 10 100 1000
Pulse Duration - tp (µs)
Peak Pulse Power - Ppk (kW)
IEC 61000-4-2 Discharge Parameters
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52005 Semtech Corp. www.semtech.com
PROTECTION PRODUCTS
SMDA05 through SMDA24
Circuit Diagram
I/O Line Protection
Device Connection for Protection of Four Data Lines
The SMDAxx series of devices are designed to protect up
to four data lines. The devices are connected as follows:
zThe SMDAxx are unidirectional devices and are
designed for use on lines where the normal operat-
ing voltage is above ground. Pins 1, 2, 3, and 4 are
connected to the protected lines. Pins 5, 6, 7, and 8
are 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:
zPlace the TVS near the input terminals or connectors
to restrict transient coupling.
zMinimize the path length between the TVS and the
protected line.
zMinimize all conductive loops including power and
ground loops.
zThe ESD transient return path to ground should be
kept as short as possible.
zNever run critical signals near board edges.
zUse ground planes whenever possible.
Matte Tin Lead Finish
Matte tin has become the industry standard lead-free
replacement for SnPb lead finishes. A matte tin finish is
composed of 100% tin solder with large grains. Since
the solder volume on the leads is small compared to the
solder paste volume that is placed on the land pattern of
the PCB, the reflow profile will be determined by the
requirements of the solder paste. Therefore, these
devices are compatible with both lead-free and SnPb
assembly techniques. In addition, unlike other lead-free
compositions, matte tin does not have any added alloys
that can cause degradation of the solder joint.
1
2
3
45
6
7
8
1
2
3
45
6
7
8
Ground
From Connector
To Protected
Device
Typical Connection
Applications Information
62005 Semtech Corp. www.semtech.com
PROTECTION PRODUCTS
PROTECTION PRODUCTS
SMDA05 through SMDA24
Land Pattern - SO-8
Outline Drawing - SO-8
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3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
-B-
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
DATUMS AND TO BE DETERMINED AT DATUM PLANE
NOTES:
1.
2. -A- -H-
REFERENCE JEDEC STD MS-012, VARIATION AA.
4.
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8
.010
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0.25
1.27 BSC
6.00 BSC
3.90
4.90
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DIM MIN
MILLIMETERS
NOM
DIMENSIONS
INCHES
MIN MAX MAXNOM
E
(.205) (5.20)
Z
G
Y
P
(C) 3.00
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1.27
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0.60.024
2.20.087
7.40.291
X
INCHES
DIMENSIONS
Z
P
Y
X
DIM
C
G
MILLIMETERS
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
NOTES:
1.
REFERENCE IPC-SM-782A, RLP NO. 300A.
2.
72005 Semtech Corp. www.semtech.com
PROTECTION PRODUCTS
SMDA05 through SMDA24
Contact Information
Semtech Corporation
Protection Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
Ordering Information
Note: Lead-free devices are RoHS/WEEE Compliant
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