© Semiconductor Components Industries, LLC, 2007
July, 2007 - Rev. 5
1Publication Order Number:
1N5908/D
1N5908
Preferred Device
1500 Watt Mosorbt Zener
Transient Voltage Suppressors
Unidirectional*
Mosorb devices are 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. These devices are
ONSemiconductor's exclusive, cost‐effective, highly reliable
Surmetic axial leaded package and are ideally‐suited for use in
communication systems, numerical controls, process controls,
medical equipment, business machines, power supplies and many
other industrial/consumer applications, to protect CMOS, MOS and
Bipolar integrated circuits.
Features
Working Peak Reverse Voltage Range - 5.0 V
Peak Power - 1500 Watts @ 1 ms
Maximum Clamp Voltage @ Peak Pulse Current
Low Leakage < 5 mA Above 10 V
Response Time is Typically < 1 ns
These are Pb-Free Devices*
Mechanical Characteristics
CASE: Void‐free, transfer‐molded, thermosetting plastic
FINISH: All external surfaces are corrosion resistant and leads are
readily solderable
MAXIMUM LEAD TEMPERATURE FOR SOLDERING PURPOSES:
260°C, 1/16 from the case for 10 seconds
POLARITY: Cathode indicated by polarity band
MOUNTING POSITION: Any
*For additional information on our Pb-Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
Preferred devices are recommended choices for future use
and best overall value.
A = Assembly Location
1N5908 = JEDEC Device Number
YY = Year
WW = Work Week
= Pb-Free Package
MARKING DIAGRAM
A
1N
5908
YYWW
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AXIAL LEAD
CASE 41A
PLASTIC
Cathode Anode
Device Package Shipping
ORDERING INFORMATION
1N5908G Axial Lead
(Pb-Free)
500 Units/Box
1N5908RL4G Axial Lead
(Pb-Free)
1500/Tape & Reel
For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
(Note: Microdot may be in either location)
Uni-Directional TVS
IPP
IF
V
I
IR
IT
VRWM
VCVBR
VF
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MAXIMUM RATINGS
Rating Symbol Value Unit
Peak Power Dissipation (Note 1) @ TL 25°C PPK 1500 W
Steady State Power Dissipation
@ TL 75°C, Lead Length = 3/8
Derated above TL = 75°C
PD5.0
50
W
mW/°C
Thermal Resistance, Junction-to-Lead RqJL 20 °C/W
Forward Surge Current (Note 2) @ TA = 25°C IFSM 200 A
Operating and Storage Temperature Range TJ, Tstg -65 to +175 °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. Nonrepetitive current pulse per Figure 4 and derated above TA = 25°C per Figure 2.
2. 1/2 sine wave (or equivalent square wave), PW = 8.3 ms, duty cycle = 4 pulses per minute maximum.
*Bidirectional device will not be available in this device
ELECTRICAL CHARACTERISTICS (TA = 25°C unless
otherwise noted, VF = 3.5 V Max. @ IF (Note 3) = 100 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
ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted, VF = 3.5 V Max. @ IF (Note 3) = 53 A)
Device
(Note 4)
VRWM
(Note 5) IR @ VRWM
Breakdown Voltage VC (Volts) (Note 7)
VBR (Note 6) (Volts) @ IT
@ IPP = 120 A @ IPP = 60 A @ IPP = 30 A
(Volts) (mA) Min Nom Max (mA)
1N5908 5.0 300 6.0 - - 1.0 8.5 8.0 7.6
3. Square waveform, PW = 8.3 ms, Non-repetitive duty cycle.
4. 1N5908 is JEDEC registered as a unidirectional device only (no bidirectional option)
5. A transient suppressor is normally selected according to the maximum working peak reverse voltage (VRWM), which should be equal to or
greater than the dc or continuous peak operating voltage level.
6. VBR measured at pulse test current IT at an ambient temperature of 25°C and minimum voltages in VBR are to be controlled.
7. Surge current waveform per Figure 4 and derate per Figure 2 of the General Data - 1500 W at the beginning of this group
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Figure 1. Pulse Rating Curve
100
80
60
40
20
00 25 50 75 100 125 150 175 200
PEAK PULSE DERATING IN % OF
PEAK POWER OR CURRENT @ TA= 25 C°
TA, AMBIENT TEMPERATURE (°C)
Figure 2. Pulse Derating Curve
5
4
3
2
1
25 50 75 100 125 150 175 200
PD, STEADY STATE POWER DISSIPATION (WATTS)
TL, LEAD TEMPERATURE (°C)
3/8
3/8
Figure 3. Steady State Power Derating
0
0
100
50
001 2 3 4
t, TIME (ms)
VALUE (%)
tr 10ms
tP
PEAK VALUE - IPP
HALF VALUE - IPP
2
Figure 4. Pulse Waveform
PULSE WIDTH (tP) IS DEFINED
AS THAT POINT WHERE THE
PEAK CURRENT DECAYS TO 50%
OF IPP
.
1ms 10ms 100ms1 ms 10 ms
100
10
1
tP
, PULSE WIDTH
PPK, PEAK POWER (kW)
NONREPETITIVE
PULSE WAVEFORM
SHOWN IN FIGURE 5
0.1ms
Figure 5. 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
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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 capacitance 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. These devices have excellent response time, typically
in the picosecond range 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 5. 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 5 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 5 is multiplied by the peak power value of
Figure 1 for the same pulse, the results follow the expected
trend.
TYPICAL PROTECTION CIRCUIT
Vin
VL
V
Vin
Vin (TRANSIENT)
VL
td
V
VL
Vin (TRANSIENT)
Zin
LOAD
OVERSHOOT DUE TO
INDUCTIVE EFFECTS
tD = TIME DELAY DUE TO CAPACITIVE EFFECT
t t
Figure 6. Figure 7.
CLIPPER BIDIRECTIONAL DEVICES
1. Clipper‐bidirectional devices are available in the
1.5KEXXA series and are designated with a “CA” suffix;
for example, 1.5KE18CA. Contact your nearest ON
Semiconductor representative.
2. Clipper‐bidirectional part numbers are tested in both
directions to electrical parameters in preceeding table
(except for VF which does not apply).
3. The 1N6267A through 1N6303A series are JEDEC
registered devices and the registration does not include a
“CA” suffix. To order clipper‐bidirectional devices one
must add CA to the 1.5KE device title.
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PACKAGE DIMENSIONS
MOSORB
CASE 41A-04
ISSUE D
DIM
A
MIN MAX MIN MAX
MILLIMETERS
0.335 0.374 8.50 9.50
INCHES
B0.189 0.209 4.80 5.30
D0.038 0.042 0.96 1.06
K1.000 --- 25.40 ---
P--- 0.050 --- 1.27
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. LEAD FINISH AND DIAMETER UNCONTROLLED
IN DIMENSION P.
4. 041A-01 THRU 041A-03 OBSOLETE, NEW
STANDARD 041A-04.
D
K
P
PA
K
B
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to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
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“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer's technical experts. SCILLC does not convey any license under its patent rights
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1N5908/D
Mosorb and Surmetic is a trademark of Semiconductor Components Industries, LLC.
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