TVS Diode Array
For ESD and Latch-Up Protection
PROTECTION PRODUCTS
Description
The SMS series of TVS arrays are designed to protect
sensitive electronics from damage or latch-up due to
ESD and other voltage-induced transient events. Each
device will protect up to four lines. They are available
with operating voltages of 5V, 12V, 15V and 24V. They
are unidirectional devices and may be used on lines
where the signal polarities are above ground.
TVS diodes are solid-state devices designed specifically
for transient suppression. They feature large cross-
sectional area junctions for conducting high transient
currents. They offer desirable characteristics for board
level protection including fast response time, low
operating and clamping voltage and no device degrada-
tion.
The SMS series devices may be used to meet the
immunity requirements of IEC 61000-4-2, level 4. The
low cost SOT23-6L package makes them ideal for use
in portable electronics such as cell phones, PDA’s, and
notebook computers.
SMS05 through SMS24
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) 24A (8/20µs)
Small package for use in portable electronics
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
EIAJ SOT23-6L package
Molding compound flammability rating: UL 94V-0
Marking : Marking Code
Packaging : Tape and Reel per EIA 481
Applications
Cell phone Handsets and Accessories
Microprocessor Based Equipment
Personal Digital Assistants (PDA’s) and Pagers
Desktops PC and Servers
Notebook, Laptop, and Palmtop Computers
Portable Instrumentation
Peripherals
MP3 Players
Cordless Phones
Circuit Diagram
Schematic & PIN Configuration
SOT23-6L (Top View)
Revision 08/11/04
1
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SMS05 through SMS24
PROTECTION PRODUCTS
Absolute Maximum Rating
R ating
Peak Pulse Power (tp = 8/20µs)
ESD Voltage (HBM p er IEC 61000-4-2)
Lead Soldering Temp erature
Op erating Temp erature
Storage Temp erature
Symbol
P
p k
V
ESD
T
L
T
J
T
STG
Value
350
>25
260 (10 sec.)
-55 to +125
-55 to +150
Units
Watts
kV
°C
°C
°C
Electrical Characteristics
SMS05
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
= 5A, t
p
= 8/20µs
I
PP
= 24A, t
p
= 8/20µs
t
p
= 8/20µs
Between I/O Pins and
Ground
V
R
= 0V, f = 1MHz
325
6
20
9.8
14.5
24
400
Conditions
Minimum
Typical
Maximum
5
Units
V
V
µA
V
V
A
pF
SMS12
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
= 5A, t
p
= 8/20µs
I
PP
= 15A, t
p
= 8/20µs
t
p
= 8/20µs
Between I/O Pins and
Ground
V
R
= 0V, f = 1MHz
135
13.3
1
19
23
15
150
Conditions
Minimum
Typical
Maximum
12
Units
V
V
µA
V
V
A
pF
2004 Semtech Corp.
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SMS05 through SMS24
PROTECTION PRODUCTS
Electrical Characteristics
(Continued)
SMS15
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
= 5A, t
p
= 8/20µs
I
PP
= 12A, t
p
= 8/20µs
t
p
= 8/20µs
Between I/O Pins and
Ground
V
R
= 0V, f = 1MHz
100
16.7
1
24
29
12
125
Conditions
Minimum
Typical
Maximum
15
Units
V
V
µA
V
V
A
pF
SMS24
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
= 5A, t
p
= 8/20µs
I
PP
= 8A, t
p
= 8/20µs
t
p
= 8/20µs
Between I/O Pins and
Ground
V
R
= 0V, f = 1MHz
60
26.7
1
40
44
8
75
Conditions
Minimum
Typical
Maximum
24
Units
V
V
µA
V
V
A
pF
2004 Semtech Corp.
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SMS05 through SMS24
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
0
1
0.1
0.01
0.1
1
10
Pulse Duration - t
p
(µs)
100
1000
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
Time (µs)
20
25
30
td = I
PP
/2
e
-t
Clamping Voltage vs. Peak Pulse Current
45
Waveform
Parameters:
tr = 8µs
td = 20µs
40
Clamping Voltage - V
C
(V)
35
30
25
20
15
10
5
0
0
5
10
15
20
25
30
Peak Pulse Current - I
PP
(A)
SMS05
SMS15
SMS12
SMS24
Waveform
Parameters:
tr = 8µs
td = 20µs
Forward Voltage vs. Forward Current
5
4.5
Forward Voltage - V
F
(V)
4
3.5
3
2.5
2
1.5
1
0.5
0
0
5
10
15
20
25
30
35
40
45
Forward Current - I
F
(A)
Waveform
Parameters:
tr = 8µs
td = 20µs
2004 Semtech Corp.
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SMS05 through SMS24
PROTECTION PRODUCTS
Applications Information
Device Connection for Protection of Four Data Lines
The SMSxx is designed to protect up to four unidirec-
tional data lines. The device is connected as follows:
1. Unidirectional protection of four I/O lines is
achieved by connecting pins 1, 3, 4 and 6 to the
data lines. Pin 2 and 5 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 SMSxx near the input terminals or con-
nectors to restrict transient coupling.
Minimize the path length between the SMSxx 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 com-
pared 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.
Protection of Four Unidirectional Lines
SMSxx Circuit Diagram
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