SMDA05 through SMDA24
PROTECTION PRODUCTS
Description
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.
Unidirectional TVS Array
for Protection of Four Lines
Features
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
Mechanical Characteristics
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
Applications
RS-232 data lines
Microprocessor based equipment
Notebooks, Desktops, and Servers
Instrumentation
LAN/WAN equipment
Peripherals
Serial and Parallel Ports
Schematic & PIN Configuration
1
8
2
7
3
6
4
5
SO-8 (Top View)
Revision 08/15/06
1
www.semtech.com
SMDA05 through SMDA24
PROTECTION PRODUCTS
Absolute Maximum Rating
R ating
Peak Pulse Power (t
p
= 8/20µs)
ESD Voltage (HBM per IEC 61000-4-2)
Lead Soldering Temperature
Operating Temperature
Storage Temperature
Symbol
P
p k
V
ESD
T
L
T
J
T
STG
Value
300
>25
260 (10 sec.)
-55 to +125
-55 to +150
Units
Watts
kV
°C
°C
°C
Electrical Characteristics (T=25
o
C)
SMDA05
Parameter
Reverse Stand-Off Voltage
Reverse Breakdown Voltage
Reverse Leakage Current
Clamp ing Voltage
Clamp ing Voltage
Peak Pulse Current
Junction Cap acitance
Symbol
V
RWM
V
BR
I
R
V
C
V
C
I
P P
C
j
I
t
= 1mA
V
RWM
= 5V, T=25°C
I
PP
= 1A, t
p
= 8/20µs
I
PP
= 5A, t
p
= 8/20µs
t
p
= 8/20µs
V
R
= 0V, f = 1MHz
6
20
9.8
11
17
400
Conditions
Minimum
Typical
Maximum
5
Units
V
V
µA
V
V
A
pF
SMDA12
Parameter
Reverse Stand-Off Voltage
Reverse Breakdown Voltage
Reverse Leakage Current
Clamp ing Voltage
Clamp ing Voltage
Peak Pulse Current
Junction Cap acitance
Symbol
V
RWM
V
BR
I
R
V
C
V
C
I
P P
C
j
I
t
= 1mA
V
RWM
= 12V, T=25°C
I
PP
= 1A, t
p
= 8/20µs
I
PP
= 5A, t
p
= 8/20µs
t
p
= 8/20µs
V
R
= 0V, f = 1MHz
13.3
1
19
24
12
150
Conditions
Minimum
Typical
Maximum
12
Units
V
V
µA
V
V
A
pF
2005 Semtech Corp.
2
www.semtech.com
SMDA05 through SMDA24
PROTECTION PRODUCTS
Electrical Characteristics
(Continued)
SMDA15
Parameter
Reverse Stand-Off Voltage
Reverse Breakdown Voltage
Reverse Leakage Current
Clamp ing Voltage
Clamp ing Voltage
Peak Pulse Current
Junction Cap acitance
Symbol
V
RWM
V
BR
I
R
V
C
V
C
I
P P
C
j
I
t
= 1mA
V
RWM
= 15V, T=25°C
I
PP
= 1A, t
p
= 8/20µs
I
PP
= 5A, t
p
= 8/20µs
t
p
= 8/20µs
V
R
= 0V, f = 1MHz
16.7
1
24
30
10
100
Conditions
Minimum
Typical
Maximum
15
Units
V
V
µA
V
V
A
pF
SMDA24
Parameter
Reverse Stand-Off Voltage
Reverse Breakdown Voltage
Reverse Leakage Current
Clamp ing Voltage
Clamp ing Voltage
Peak Pulse Current
Junction Cap acitance
Symbol
V
RWM
V
BR
I
R
V
C
V
C
I
P P
C
j
I
t
= 1mA
V
RWM
= 24V, T=25°C
I
PP
= 1A, t
p
= 8/20µs
I
PP
= 5A, t
p
= 8/20µs
t
p
= 8/20µs
V
R
= 0V, f = 1MHz
26.7
1
43
55
5
60
Conditions
Minimum
Typical
Maximum
24
Units
V
V
µA
V
V
A
pF
2005 Semtech Corp.
3
www.semtech.com
SMDA05 through SMDA24
PROTECTION PRODUCTS
Typical Characteristics
Non-Repetitive Peak Pulse Power vs. Pulse Time
10
Peak Pulse Power - P
pk
(kW)
Power Derating Curve
110
100
90
% of Rated Power or I
PP
80
70
60
50
40
30
20
10
1
0.1
0.01
0.1
1
10
Pulse Duration - t
p
(µs)
100
1000
0
0
25
50
75
100
o
125
150
Ambient Temperature - T
A
( C)
Pulse Waveform
110
100
90
80
Percent of I
PP
70
60
50
40
30
20
10
0
0
5
10
15
T im e (µs)
20
25
30
td = I
PP
/2
e
-t
W aveform
Parameters:
tr = 8µs
td = 20µs
ESD Pulse Waveform (IEC 61000-4-2)
Level
IEC 61000-4-2 Discharge Parameters
First
Peak
Current
(A )
1
2
3
4
7.5
15
22.5
30
Peak
Current
at 30 ns
(A )
4
8
12
16
Peak
Current
at 60 ns
(A )
8
4
6
8
Test
Test
Voltage
Voltage
(Contact
(A ir
Discharge) Discharge)
(kV)
(kV)
2
4
6
8
2
4
8
15
2005 Semtech Corp.
4
www.semtech.com
SMDA05 through SMDA24
PROTECTION PRODUCTS
Applications Information
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:
The 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:
Place the TVS near the input terminals or connectors
to restrict transient coupling.
Minimize the path length between the TVS and the
protected line.
Minimize all conductive loops including power and
ground loops.
The ESD transient return path to ground should be
kept as short as possible.
Never run critical signals near board edges.
Use 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.
Typical Connection
To Protected
Device
1
8
Circuit Diagram
1
8
2
7
3
6
4
5
I/O Line Protection
2
7
Ground
3
6
4
5
From Connector
2005 Semtech Corp.
5
www.semtech.com
Embedded System
京公网安备 11010802033920号
EEWORLD
