1Publication Order Number:
1SMB5.0AT3/D
1SMB5.0AT3G Series,
SZ1SMB5.0AT3G Series
600 Watt Peak Power Zener
Transient Voltage
Suppressors
Unidirectional
The SMB series is designed to protect voltage
sensitive components from high voltage, high energy transients.
They have excellent clamping capability, high surge capability,
low zener impedance and fast response time. The SMB series is
supplied in the Littelfuse exclusive, cost-effective, highly
reliable package and is ideally suited for use in
communication systems, automotive, numerical controls, process
controls, medical equipment, business machines, power supplies and
many other industrial/consumer applications.
Features
Working Peak Reverse Voltage Range − 5.0 V to 170 V
Standard Zener Breakdown Voltage Range − 6.7 V to 199 V
Peak Power − 600 W @ 1.0 ms
ESD Rating of Class 3 (> 16 kV) per Human Body Model
Maximum Clamp Voltage @ Peak Pulse Current
Low Leakage < 5.0 mA Above 10 V
UL 497B for Isolated Loop Circuit Protection
Response Time is Typically < 1.0 ns
SZ Prefix for Automotive and Other Applications Requiring Unique
Site and Control Change Requirements; AEC−Q101 Qualified and
PPAP Capable
Pb−Free Packages are Available
Mechanical Characteristics
CASE: Void-free, transfer-molded, thermosetting plastic
FINISH: All external surfaces are corrosion resistant and leads are
readily solderable
MAXIMUM CASE TEMPERATURE FOR SOLDERING PURPOSES:
260C for 10 Seconds
LEADS: Modified L−Bend providing more contact area to bond pads
POLARITY: Cathode indicated by polarity band
MOUNTING POSITION: Any
PLASTIC SURFACE MOUNT
ZENER OVERVOLTAGE
TRANSIENT SUPPRESSORS
5.0 V − 170 V,
600 W PEAK POWER
Device Package Shipping
ORDERING INFORMATION
SMB
CASE 403A
PLASTIC
Cathode Anode
Littelfuse.com
1SMBxxxAT3G SMB
(Pb−Free)
2,500 /
Tape & Reel
See specific marking information in the device marking
column of the Electrical Characteristics table on page 3 of
this data sheet.
DEVICE MARKING INFORMATION
A = Assembly Location
Y = Year
WW = Work Week
xx = Device Code (Refer to page 3)
G= Pb−Free Package
MARKING DIAGRAM
AYWW
xx G
G
(Note: Microdot may be in either location)
SZ1SMBxxxAT3G SMB
(Pb−Free)
2,500 /
Tape & Reel
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
OBSOLETE/EOL
DATE June/30/2018 PCN/ECN# LFPCN41246
REPLACED BY SMBJ Series
Uni−Directional TVS
IPP
IF
V
I
IR
IT
VRWM
VCVBR
VF
1SMB5.0AT3G Series, SZ1SMB5.0AT3G Series
MAXIMUM RATINGS
Rating Symbol Value Unit
Peak Power Dissipation (Note 1) @ TL = 25C, Pulse Width = 1 ms PPK 600 W
DC Power Dissipation @ TL = 75C Measured Zero Lead Length (Note 2)
Derate Above 75C
Thermal Resistance from Junction−to−Lead
PD
RqJL
3.0
40
25
W
mW/C
C/W
DC Power Dissipation (Note 3) @ TA = 25C
Derate Above 25C
Thermal Resistance from Junction−to−Ambient
PD
RqJA
0.55
4.4
226
W
mW/C
C/W
Forward Surge Current (Note 4) @ TA = 25C IFSM 100 A
Operating and Storage Temperature Range TJ, Tstg −65 to +150 C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. 10 X 1000 ms, non−repetitive.
2. 1 in square copper pad, FR−4 board.
3. FR−4 board, using minimum recommended footprint, as shown in 403A case outline dimensions spec.
4. 1/2 sine wave (or equivalent square wave), PW = 8.3 ms, duty cycle = 4 pulses per minute maximum.
ELECTRICAL CHARACTERISTICS (TA = 25C unless
otherwise noted, VF = 3.5 V Max. @ IF (Note 5) = 30 A)
Symbol Parameter
IPP Maximum Reverse Peak Pulse Current
VCClamping Voltage @ IPP
VRWM Working Peak Reverse Voltage
IRMaximum Reverse Leakage Current @ VRWM
VBR Breakdown Voltage @ IT
ITTest Current
IFForward Current
VFForward Voltage @ IF
5. 1/2 sine wave (or equivalent square wave), PW = 8.3 ms,
non−repetitive duty cycle.
2Publication Order Number:
1SMB5.0AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
1SMB5.0AT3G Series, SZ1SMB5.0AT3G Series
ELECTRICAL CHARACTERISTICS
Device*
Device
Marking
VRWM
(Note 6) IR @ VRWM
Breakdown Voltage VC @ IPP (Note 8) Ctyp
(Note 9)
VBR (Note 7) Volts @ ITVCIPP
VmAMin Nom Max mA V A pF
1SMB5.0AT3G
1SMB6.0AT3G
1SMB6.5AT3G
1SMB7.0AT3G
KE
KG
KK
KM
5.0
6.0
6.5
7.0
800
800
500
500
6.40
6.67
7.22
7.78
6.7
7.02
7.6
8.19
7.0
7.37
7.98
8.6
10
10
10
10
9.2
10.3
11.2
12.0
65.2
58.3
53.6
50.0
2700
2300
2140
2005
1SMB7.5AT3G
1SMB8.0AT3G
1SMB8.5AT3G
1SMB9.0AT3G
KP
KR
KT
KV
7.5
8.0
8.5
9.0
100
50
10
5.0
8.33
8.89
9.44
10.0
8.77
9.36
9.92
10.55
9.21
9.83
10.4
11.1
1.0
1.0
1.0
1.0
12.9
13.6
14.4
15.4
46.5
44.1
41.7
39.0
1890
1780
1690
1605
1SMB10AT3G
1SMB11AT3G
1SMB12AT3G
1SMB13AT3G
KX
KZ
LE
LG
10
11
12
13
5.0
5.0
5.0
5.0
11.1
12.2
13.3
14.4
11.7
12.85
14
15.15
12.3
13.5
14.7
15.9
1.0
1.0
1.0
1.0
17.0
18.2
19.9
21.5
35.3
33.0
30.2
27.9
1460
1345
1245
1160
1SMB14AT3G
1SMB15AT3G
1SMB16AT3G
1SMB17AT3G
LK
LM
LP
LR
14
15
16
17
5.0
5.0
5.0
5.0
15.6
16.7
17.8
18.9
16.4
17.6
18.75
19.9
17.2
18.5
19.7
20.9
1.0
1.0
1.0
1.0
23.2
24.4
26.0
27.6
25.8
24.0
23.1
21.7
1085
1020
965
915
1SMB18AT3G
1SMB20AT3G
1SMB22AT3G
1SMB24AT3G
LT
LV
LX
LZ
18
20
22
24
5.0
5.0
5.0
5.0
20.0
22.2
24.4
26.7
21.05
23.35
25.65
28.1
22.1
24.5
26.9
29.5
1.0
1.0
1.0
1.0
29.2
32.4
35.5
38.9
20.5
18.5
16.9
15.4
870
790
730
675
1SMB26AT3G
1SMB28AT3G
1SMB30AT3G
1SMB33AT3G
ME
MG
MK
MM
26
28
30
33
5.0
5.0
5.0
5.0
28.9
31.1
33.3
36.7
30.4
32.75
35.05
38.65
31.9
34.4
36.8
40.6
1.0
1.0
1.0
1.0
42.1
45.4
48.4
53.3
14.2
13.2
12.4
11.3
630
590
555
510
1SMB36AT3G
1SMB40AT3G
1SMB43AT3G
1SMB45AT3G
MP
MR
MT
MV
36
40
43
45
5.0
5.0
5.0
5.0
40.0
44.4
47.8
50.0
42.1
46.75
50.3
52.65
44.2
49.1
52.8
55.3
1.0
1.0
1.0
1.0
58.1
64.5
69.4
72.7
10.3
9.3
8.6
8.3
470
430
400
385
1SMB48AT3G
1SMB51AT3G
1SMB54AT3G
1SMB58AT3G
MX
MZ
NE
NG
48
51
54
58
5.0
5.0
5.0
5.0
53.3
56.7
60.0
64.4
56.1
59.7
63.15
67.8
58.9
62.7
66.3
71.2
1.0
1.0
1.0
1.0
77.4
82.4
87.1
93.6
7.7
7.3
6.9
6.4
365
345
330
310
1SMB60AT3G
1SMB64AT3G
1SMB70AT3G
1SMB75AT3G
NK
NM
NP
NR
60
64
70
75
5.0
5.0
5.0
5.0
66.7
71.1
77.8
83.3
70.2
74.85
81.9
87.7
73.7
78.6
86
92.1
1.0
1.0
1.0
1.0
96.8
103
113
121
6.2
5.8
5.3
4.9
300
280
260
245
1SMB85AT3G
1SMB90AT3G
1SMB100AT3G
NV
NX
NZ
85
90
100
55.0
5.0
5.0
94.4
100
111
99.2
105.5
117
104
111
123
1.0
1.0
1.0
137
146
162
4.4
4.1
3.7
220
210
190
1SMB110AT3G
1SMB120AT3G
1SMB130AT3G
1SMB150AT3G
PE
PG
PK
PM
110
120
130
150
5.0
5.0
5.0
5.0
122
133
144
167
128.5
140
151.5
176
135
147
159
185
1.0
1.0
1.0
1.0
177
193
209
243
3.4
3.1
2.9
2.5
175
160
150
135
1SMB160AT3G
1SMB170AT3G
PP
PR
160
170
5.0
5.0
178
189
187.5
199
197
209
1.0
1.0
259
275
2.3
2.2
125
120
6. A transient suppressor is normally selected according to the working peak reverse voltage (VRWM), which should be equal to or greater than
the DC or continuous peak operating voltage level.
7. VBR measured at pulse test current IT at an ambient temperature of 25C.
8. Surge current waveform per Figure 2 and derate per Figure 4 of the General Data − 600 W at the beginning of this group.
9. Bias Voltage = 0 V, F = 1 MHz, TJ = 25C
†Please see 1SMB10CAT3 to 1SMB78CAT3 for Bidirectional devices.
* Include SZ-prefix devices where applicable.
3Publication Order Number:
1SMB5.0AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
1SMB5.0AT3G Series, SZ1SMB5.0AT3G Series
1SMB5.0AT3G
1SMB10AT3G
1SMB48AT3G
1SMB170AT3G
NONREPETITIVE
PULSE WAVEFORM
SHOWN IN FIGURE 2
tP
, PULSE WIDTH
1
10
100
0.1 ms1 ms10 ms 100 ms1 ms 10 ms
0.1
Figure 1. Pulse Rating Curve
01 2 34
0
50
100
t, TIME (ms)
VALUE (%)
HALF VALUE - IPP
2
PEAK VALUE - IPP
tr 10 ms
Figure 2. Pulse Waveform
Figure 3. Pulse Derating Curve
Vin VL
Zin
LOAD
Figure 4. Typical Junction Capacitance vs.
Bias Voltage
PEAK PULSE DERATING IN % OF
PEAK POWER OR CURRENT @ T
A= 25 C
100
80
60
40
20
00 25 50 75 100 125 150
TA, AMBIENT TEMPERATURE (C)
120
140
160
tP
PULSE WIDTH (tP) IS DEFINED AS
THAT POINT WHERE THE PEAK
CURRENT DECAYS TO 50% OF
IPP
.
BIAS VOLTAGE (VOLTS)
Figure 5. Typical Protection Circuit
1 10 100 1000
10
100
1000
10,000
C, CAPACITANCE (pF)
PPK, PEAK POWER (kW)
1
TJ = 25C
f = 1 MHz
5
4Publication Order Number:
1SMB5.0AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
1SMB5.0AT3G Series, SZ1SMB5.0AT3G Series
APPLICATION NOTES
Response Time
In most applications, the transient suppressor device is
placed in parallel with the equipment or component to be
protected. In this situation, there is a time delay associated
with the capacitance of the device and an overshoot
condition associated with the inductance of the device and
the inductance of the connection method. The capacitive
effect is of minor importance in the parallel protection
scheme because it only produces a time delay in the
transition from the operating voltage to the clamp voltage as
shown in Figure 6.
The inductive effects in the device are due to actual
turn-on time (time required for the device to go from zero
current to full current) and lead inductance. This inductive
effect produces an overshoot in the voltage across the
equipment or component being protected as shown in
Figure 7. Minimizing this overshoot is very important in the
application, since the main purpose for adding a transient
suppressor is to clamp voltage spikes. The SMB series have
a very good response time, typically < 1.0 ns and negligible
inductance. However, external inductive effects could
produce unacceptable overshoot. Proper circuit layout,
minimum lead lengths and placing the suppressor device as
close as possible to the equipment or components to be
protected will minimize this overshoot.
Some input impedance represented by Zin is essential to
prevent overstress of the protection device. This impedance
should be as high as possible, without restricting the circuit
operation.
Duty Cycle Derating
The data of Figure 1 applies for non-repetitive conditions
and at a lead temperature of 25C. If the duty cycle increases,
the peak power must be reduced as indicated by the curves
of Figure 8. Average power must be derated as the lead or
ambient temperature rises above 25C. The average power
derating curve normally given on data sheets may be
normalized and used for this purpose.
At first glance the derating curves of Figure 8 appear to be
in error as the 10 ms pulse has a higher derating factor than
the 10 ms pulse. However, when the derating factor for a
given pulse of Figure 8 is multiplied by the peak power
value of Figure 1 for the same pulse, the results follow the
expected trend.
VL
V
Vin
Vin (TRANSIENT)
VL
td
V
Vin (TRANSIENT)
OVERSHOOT DUE TO
INDUCTIVE EFFECTS
tD = TIME DELAY DUE TO CAPACITIVE EFFECT
t t
Figure 6. Figure 7.
Figure 8. Typical Derating Factor for Duty Cycle
DERATING FACTOR
1 ms
10 ms
1
0.7
0.5
0.3
0.05
0.1
0.2
0.01
0.02
0.03
0.07
100 ms
0.1 0.2 0.5 2 5 10 501 20 100
D, DUTY CYCLE (%)
PULSE WIDTH
10 ms
5Publication Order Number:
1SMB5.0AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
1SMB5.0AT3G Series, SZ1SMB5.0AT3G Series
UL RECOGNITION
The entire series has Underwriters Laboratory
Recognition for the classification of protectors (QVGQ2)
under the UL standard for safety 497B and File .
Many competitors only have one or two devices recognized
or have recognition in a non-protective category. Some
competitors have no recognition at all. With the UL497B
recognition, our parts successfully passed several tests
including Strike Voltage Breakdown test, Endurance
Conditioning, Temperature test, Dielectric
Voltage-Withstand test, Discharge test and several more.
Whereas, some competitors have only passed a
flammability test for the package material, we have been
recognized for much more to be included in their Protector
category.
6Publication Order Number:
1SMB5.0AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
#E128662
1SMB5.0AT3G Series, SZ1SMB5.0AT3G Series
PACKAGE DIMENSIONS
SMB
CASE 403A−03
ISSUE H
E
bD
c
L1
L
A
A1
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. D DIMENSION SHALL BE MEASURED WITHIN DIMENSION P.
2.261
0.089
2.743
0.108
2.159
0.085 ǒmm
inchesǓ
SCALE 8:1
SOLDERING FOOTPRINT
DIM
A
MIN NOM MAX MIN
MILLIMETERS
1.90 2.20 2.28 0.075
INCHES
A1 0.05 0.10 0.19 0.002
b1.96 2.03 2.20 0.077
c0.15 0.23 0.31 0.006
D3.30 3.56 3.95 0.130
E4.06 4.32 4.60 0.160
L0.76 1.02 1.60 0.030
0.087 0.090
0.004 0.007
0.080 0.087
0.009 0.012
0.140 0.156
0.170 0.181
0.040 0.063
NOM MAX
5.21 5.44 5.60 0.205 0.214 0.220
HE
0.51 REF 0.020 REF
D
L1
HE
POLARITY INDICATOR
OPTIONAL AS NEEDED
7Publication Order Number:
1SMB5.0AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 13
Littelfuse.com
Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product
selected for their own applications. Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation,
military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any
other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than
those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for
any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of
products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse
products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse.
