1Publication Order Number:
P6SMB6.8AT3/D
P6SMB6.8AT3G Series,
SZP6SMB6.8AT3G 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.
Specification Features:
•Working Peak Reverse Voltage Range − 5.8 to 171 V
•Standard Zener Breakdown Voltage Range − 6.8 to 200 V
•Peak Power − 600 W @ 1 ms
•ESD Rating of Class 3 (> 16 kV) per Human Body Model
•Maximum Clamp Voltage @ Peak Pulse Current
•Low Leakage < 5 mA Above 10 V
•UL 497B for Isolated Loop Circuit Protection
•Response Time is Typically < 1 ns
•SZ Prefix for Automotive and Other Applications Requiring Unique
Site and Control Change Requirements; AEC−Q101 Qualified and
PPAP Capable
•These Devices are Pb−Free and are RoHS Compliant
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:
260°C for 10 Seconds
LEADS: Modified L−Bend providing more contact area to bond pads
POLARITY: Cathode indicated by polarity band
MOUNTING POSITION: Any
*Please see P6SMB11CAT3 to P6SMB91CAT3 for Bidirectional devices.
PLASTIC SURFACE MOUNT
ZENER OVERVOLTAGE
TRANSIENT SUPPRESSORS
5.8−171 VOLTS
600 WATT PEAK POWER
Cathode Anode
Device Package Shipping
ORDERING INFORMATION
SMB
CASE 403A
PLASTIC
P6SMBxxxAT3G SMB
(Pb−Free)
2,500 /
Tape & Reel
A = Assembly Location
Y = Year
WW = Work Week
xx = Device Code (Refer to page 3)
G= Pb−Free Package
MARKING DIAGRAM
(Note: Microdot may be in either location)
AYWW
xx G
G
SZP6SMBxxxAT3G SMB
(Pb−Free)
2,500 /
Tape & Reel
Littelfuse.com
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
OBSOLETE/EOL
DATE June/30/2018 PCN/ECN# LFPCN41246
REPLACED BY P6SMB Series
Uni−Directional TVS
IPP
IF
V
I
IR
IT
VRWM
VCVBR
VF
P6SMB6.8AT3G Series, SZP6SMB6.8AT3G Series
MAXIMUM RATINGS
Rating Symbol Value Unit
Peak Power Dissipation (Note 1) @ TL = 25°C, Pulse Width = 1 ms PPK 600 W
DC Power Dissipation @ TL = 75°C Measured Zero Lead Length (Note 2)
Derate Above 75°C
Thermal Resistance from Junction−to−Lead
PD
RqJL
3.0
40
25
W
mW/°C
°C/W
DC Power Dissipation (Note 3) @ TA = 25°C
Derate Above 25°C
Thermal Resistance from Junction−to−Ambient
PD
RqJA
0.55
4.4
226
W
mW/°C
°C/W
Forward Surge Current (Note 4) @ TA = 25°C IFSM 100 A
Operating and Storage Temperature Range TJ, Tstg −65 to +150 °C
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
1. 10 X 1000 ms, non−repetitive
2. 1″ square copper pad, FR−4 board
3. FR−4 board, using Littelfuse 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 = 25°C unless otherwise noted, VF = 3.5 V Max. @ IF
(Note 4) = 30 A, VF = 1.3 V Max. @ IF (Note 4) = 3 A) (Note 5)
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
QVBR Maximum Temperature Coefficient of VBR
IFForward Current
VFForward Voltage @ IF
5. 1/2 sine wave or equivalent, PW = 8.3 ms, non−repetitive
duty cycle
2Publication Order Number:
P6SMB6.8AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
P6SMB6.8AT3G Series, SZP6SMB6.8AT3G Series
ELECTRICAL CHARACTERISTICS
Device* Device
Marking
VRWM
(Note 6
)
IR @
VRWM
Breakdown Voltage VC @ IPP (Note 8)
QVBR
Ctyp
(Note 9)
VBR V (Note 7) @ ITVCIPP
VmAMin Nom Max mA V A %/°C pF
P6SMB6.8AT3G
P6SMB7.5AT3G
P6SMB8.2AT3G
P6SMB9.1AT3G
6V8A
7V5A
8V2A
9V1A
5.8
6.4
7.02
7.78
1000
500
200
50
6.45
7.13
7.79
8.65
6.8
7.51
8.2
9.1
7.14
7.88
8.61
9.55
10
10
10
1
10.5
11.3
12.1
13.4
57
53
50
45
0.057
0.061
0.065
0.068
2380
2180
2015
1835
P6SMB10AT3G
P6SMB12AT3G
P6SMB13AT3G
10A
12A
13A
8.55
10.2
11.1
10
5
5
9.5
11.4
12.4
10
12
13.05
10.5
12.6
13.7
1
1
1
14.5
16.7
18.2
41
36
33
0.073
0.078
0.081
1690
1435
1335
P6SMB15AT3G
P6SMB16AT3G
P6SMB18AT3G
P6SMB20AT3G
15A
16A
18A
20A
12.8
13.6
15.3
17.1
5
5
5
5
14.3
15.2
17.1
19
15.05
16
18
20
15.8
16.8
18.9
21
1
1
1
1
21.2
22.5
25.2
27.7
28
27
24
22
0.084
0.086
0.088
0.09
1175
1110
1000
910
P6SMB22AT3G
P6SMB24AT3G
P6SMB27AT3G
P6SMB30AT3G
22A
24A
27A
30A
18.8
20.5
23.1
25.6
5
5
5
5
20.9
22.8
25.7
28.5
22
24
27.05
30
23.1
25.2
28.4
31.5
1
1
1
1
30.6
33.2
37.5
41.4
20
18
16
14.4
0.092
0.094
0.096
0.097
835
775
700
635
P6SMB33AT3G
P6SMB36AT3G
P6SMB39AT3G
P6SMB43AT3G
33A
36A
39A
43A
28.2
30.8
33.3
36.8
5
5
5
5
31.4
34.2
37.1
40.9
33.05
36
39.05
43.05
34.7
37.8
41
45.2
1
1
1
1
45.7
49.9
53.9
59.3
13.2
12
11.2
10.1
0.098
0.099
0.1
0.101
585
540
500
460
P6SMB47AT3G
P6SMB51AT3G
P6SMB56AT3G
P6SMB62AT3G
47A
51A
56A
62A
40.2
43.6
47.8
53
5
5
5
5
44.7
48.5
53.2
58.9
47.05
51.05
56
62
49.4
53.6
58.8
65.1
1
1
1
1
64.8
70.1
77
85
9.3
8.6
7.8
7.1
0.101
0.102
0.103
0.104
425
395
365
335
P6SMB68AT3G
P6SMB75AT3G
P6SMB91AT3G
68A
75A
91A
58.1
64.1
77.8
5
5
5
64.6
71.3
86.5
68
75.05
91
71.4
78.8
95.5
1
1
1
92
103
125
6.5
5.8
4.8
0.104
0.105
0.106
305
280
235
P6SMB100AT3G
P6SMB120AT3G
P6SMB130AT3G
100A
120A
130A
85.5
102
111
5
5
5
95
114
124
100
120
130.5
105
126
137
1
1
1
137
165
179
4.4
3.6
3.3
0.106
0.107
0.107
215
185
170
P6SMB150AT3G
P6SMB160AT3G
P6SMB180AT3G
150A
160A
180A
128
136
154
5
5
5
143
152
171
150.5
160
180
158
168
189
1
1
1
207
219
246
2.9
2.7
2.4
0.108
0.108
0.108
150
140
130
P6SMB200AT3G 200A 171 5 190 200 210 1 274 2.2 0.108 115
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 25°C.
8. Surge current waveform per Figure 2 and derate per Figure 3.
9. Bias Voltage = 0 V, F = 1 MHz, TJ = 25°C
* Include SZ-prefix devices where applicable.
3Publication Order Number:
P6SMB6.8AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
P6SMB6.8AT3G Series, SZP6SMB6.8AT3G Series
P , PEAK POWER (kW)
P
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
01234
0
50
100
t, TIME (ms)
VALUE (%)
HALF VALUE - IPP
2
PEAK VALUE - IPP
tr≤ 10 ms
Figure 2. Pulse Waveform
TYPICAL PROTECTION CIRCUIT
Vin VL
Zin
LOAD
Figure 3. Pulse Derating Curve
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
.
Figure 4. Typical Junction Capacitance vs.
Bias Voltage
P6SMB6.8AT3G
P6SMB18AT3G
P6SMB51AT3G
P6SMB200AT3G
BIAS VOLTAGE (VOLTS)
1 10 100 100
0
10
100
1000
10,000
C, CAPACITANCE (pF)
1
5
TJ = 25°C
f = 1 MHz
4Publication Order Number:
P6SMB6.8AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
P6SMB6.8AT3G Series, SZP6SMB6.8AT3G 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 5.
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 6. Minimizing this overshoot is very important in the
application, since the main purpose for adding a transient
suppressor is t o clamp voltage spikes. The SMB series have
a very good response time, typically < 1 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 25°C. If the duty cycle increases,
the peak power must be reduced as indicated by the curves
of Figure 7. Average power must be derated as the lead or
ambient temperature rises above 25°C. 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 7 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 7 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 5. Figure 6.
Figure 7. 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:
P6SMB6.8AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
P6SMB6.8AT3G Series, SZP6SMB6.8AT3G 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:
P6SMB6.8AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
#E128662
P6SMB6.8AT3G Series, SZP6SMB6.8AT3G Series
PACKAGE DIMENSIONS
SMB
CASE 403A−03
ISSUE J
E
bD
c
L1
L
A
A1
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION b SHALL BE MEASURED WITHIN DIMENSION L1.
2.261
0.089
2.743
0.108
2.159
0.085 ǒmm
inchesǓ
SCALE 8:1
SOLDERING FOOTPRINT
DIM
AMIN NOM MAX MIN
MILLIMETERS
1.95 2.30 2.47 0.077
INCHES
A1 0.05 0.10 0.20 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
0.091 0.097
0.004 0.008
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:
P6SMB6.8AT3/D
Specifications subject to change without notice. © 2016 Littelfuse, Inc.
September 19, 2016 − Rev. 14
Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, 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.
