PROTECTION PRODUCTS SM05 through SM36
TVS Diode Array
Description
Features
Circuit Diagram Schematic & PIN Configuration
The SM series of transient voltage suppressors (TVS)are designed to protect components which are
connected to data and transmission lines from voltage surges caused by electrostatic discharge (ESD),electrical fast transients (EFT), 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 dual-junction common-anode design allows the user to protect one bidirectional data line or two unidirectional lines. The low profile SOT23
package allows flexibility in the design of “crowded”circuit boards.
The SM series will meet the surge requirements of IEC 61000-4-2 (Formerly IEC 801-2), Level 4, “Human Body Model” for air and contact discharge.
Applications
Mechanical Characteristics
Cellular Handsets and Accessories Portable Electronics Industrial Controls Set-Top Box
Servers, Notebook, and Desktop PC
300 watts peak pulse power (t p = 8/20μs) Transient protection for data & power 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)
Protects one bidirectional line or two unidirectional lines
Working Voltages: 5V, 12V, 15V, 24 and 36V Low clamping voltage
Solid-state silicon avalanche technology
JEDEC SOT23 package
Molding compound flammability rating: UL 94V-0 Marking : Marking Code
Packaging : Tape and Reel per EIA 481
2
1
M
S
r e t e
m
a r a
P l o
b
m
y S s n
o i t i d
n
o
C m
u
m i n i
M l a c i p y T m
u
m i x a
M s t i n
U
e g a t l o V
f f O-d
n a t S
e s r e v e
R V
M
W
R
2
1V
e g a t l o V
n
w
o
d k a
e r B
e s r e v e
R V
R
B I
t
A
m
1
=3.3
1V
t n e r r u
C
e g a k a e L
e s r e v e
R I
R V
M
W
R
C
°
5
2
=
T,V
2
1
=1A
μ
e g a t l o V
g n i p
m
a l C V
C
I
P
P
,A
1
=
t
p
sμ
2/8
=
9
1V
t n e r r u
C
e s l u
P
k a e
P I
P
P t
p
sμ
2/8
=2
1A
e c n a t i c a
p a
C
n o i t c n
u J C
j
2
o t
1
n i P
V
R
z H
M
1
=
f,V
=
2
1F p
e c n a t i c a
p a
C
n o i t c n
u J C
j
d
n a
3
o t
1
n i P
3
o t
2
n i P
V
R
z H
M
1
=
f,V
=
5
1F p
4
2
M
S
r e t e
m
a r a
P l o b
m
y S s n o i t i d n o
C m
u
m i n i
M l a c i p y T m
u
m i x a
M s t i n
U
e g a t l o V
f f O-d n a t S
e s r e v e
R V
M
W
R
42V
e g a t l o V
n
w
o d k a e r B
e s r e v e
R V
R
B I
t
A
m
1
=7.6
2V
t n e r r u C
e g a k a e L
e s r e v e
R I
R V
M
W
R
C
°
5
2
=T,V42
=1Aμ
e g a t l o V
g n i p
m
a l C V
C I
P P
t
,A1
=
p
sμ0
2/8
=3
4V
t n e r r u C
e s l u P
k a e P I
P P t
p
sμ0
2/8
=5A
e c n a t i c a p a C
n o i t c n u J C
j
2
o t
1
n i P
V
R
z H
M
1
=
f,V0
=
5F p
e c n a t i c a p a C
n o i t c n u J C
j
3
o t
2
d n a
3
o t
1
n i P
V
R
z H
M
1
=
f,V0
=
6F p
6
3
M
S
r e t e
m
a r a
P l o b
m
y S s n o i t i d n o
C m
u
m i n i
M l a c i p y T m
u
m i x a
M s t i n
U
e g a t l o V
f f O-d n a t S
e s r e v e
R V
M
W
R
6
3V
e g a t l o V
n
w
o d k a e r B
e s r e v e
R V
R
B I
t
A
m
1
=0
4V
t n e r r u C
e g a k a e L
e s r e v e
R I
R V
M
W
R
C
°
5
2
=T,V6
3
=1Aμ
e g a t l o V
g n i p
m
a l C V
C I
P P
t,A1
=
p
sμ0
2/8
=0
6V
t n e r r u C
e s l u P
k a e P I
P P t
p
sμ0
2/8
=4A
e c n a t i c a p a C
n o i t c n u J C
j
2
o t
1
n i P
V
R
z H
M
1
=
f,V0
=
4F p
e c n a t i c a p a C
n o i t c n u J C
j
3
o t
2
d n a
3
o t
1
n i P
V
R
z H
M
1
=
f,V0
=
5
4F p
Typical Characteristics
Non-Repetitive Peak Pulse Power vs. Pulse Time
1020304050607080901001100255075100
125150
Ambient Temperature - T A (o
C)
% o f R a t e d P o w e r o r I P P
Power Derating Curve
Pulse Waveform
01020304050607080901001100
5
10
1520
25
30
T im e (μs)
P e r c e n t o f I P P
l
e v e L t s r i F k a e P t n e r r u C )
A (k a e P t n e r r u C s n 03t a )A (k a e P t n e r r u C s n 06t a )A (t s
e T e g a t l o V t c a t n o C ()e g r a h c s i D )V k (t s e T e g a t l o V r i A ()e g r a h c s i D )
V k (15.74822251844435.22216684
36
18
8
5
10.01
0.1
1
100.1
1
10
100
1000
Pulse Duration - t p (μs)
P e a k P u l s e P o w e r - P p k (k W )
IEC 61000-4-2 Discharge Parameters
ESD Pulse Waveform (Per IEC 61000-4-2)
Applications Information
Device Schematic & Pin Configuration
Device Connection Options
The SM series is designed to protect one bidirectional or two unidirectional data or I/O lines operating at 5 to 36 volts. Connection options are as follows:
z Bidirectional: Pin 1 is connected to the data line
and pin 2 is connected to ground (Since the device is symmetrical, these connections may be re-versed). The ground connection should be made directly to a ground plane. The path length should be kept as short as possible to minimize parasitic inductance. Pin 3 is not connected.
z Unidirectional: Data lines are connected to pin 1
and pin 2. Pin 3 is connected to ground. For best results, this pin should be connected directly to a ground plane on the board. The path length should be kept as short as possible to minimize parasitic inductance.Circuit Board Layout Recommendations for Suppres-sion of ESD.
Good circuit board layout is critical for the suppression of fast rise-time transients such as ESD. The following guidelines are recommended (Refer to application note SI99-01 for more detailed information):
z Place the TVS near the input terminals or connec-tors to restrict transient coupling.
z Minimize the path length between the TVS and the
protected line.
z Minimize all conductive loops including power and
ground loops.
z The ESD transient return path to ground should be
kept as short as possible.
z Never run critical signals near board edges.z 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.
RS-232 Transceiver Protection Example
Outline Drawing - SOT23
Contact Information
Semtech Corporation Protection Products Division
200 Flynn Road, Camarillo, CA 93012Phone: (805)498-2111 FAX (805)498-3804
Ordering Information
r e b m u N t r a P h s i n i F d a e L r e p y t Q l e e R e z i S l e e R C T .50M S b P n S 000,3h c n I 7C T .21M S b P n S 000,3h c n I 7C T .51M S b P n S 000,3h c n I 7C T .42M S b P n S 000,3h c n I 7C T .63M S b P n S 000,3h c n I 7T C T .50M S e e r F b P 000,3h c n I 7T C T .21M S e e r F b P 000,3h c n I 7T C T .51M S e e r F b P 000,3h c n I 7T C T .42M S e e r F b P 000,3h c n I 7T
C T .63M S e
e r F b P 0
00,3h
c n I 7Marking Codes
r
e b m u N t r a P g n i k r a M e d o C 50M S 50M 21M S 21M 51M S 51M 42M S 42M 6
3M S 6
3M