OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

V300SM20

P1-P3P4-P4
Varistor Products
©2010 Littelfuse, Inc.
Revision: May 11, 2010
SM20 Series Varistor
Surface Mount Varistors > SM20 Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/sm20.html for current information.
SM20 Series
Description
The Littelfuse 20mm SMD Series is a surface-mount
metal oxide varistor device, for use in applications
requiring hi-energy / transient current capability.
The AC rated parts are designed to operate
continuously across AC power lines. The DC rated
parts are suitable for Automotive applications. The
series comprises a Nylon molded package with folded
tin plated metal leads for soldering to board.
The SMD Series is based on radial 20mm internal
varistor element with similar characteristics to
the Littelfuse LA / ZA series of varistors.
Features
• DC Voltage
Rating 26VDC
• AC Voltage Rating
175 - 320AC
• No De-Rating up
to 85°C ambient
• Lead-Free, Halogen-
Free and RoHS
Compliant
• Low voltage
devices specified
for automotive load
dump energy
• Available in "waffle"
tray packaging
Agency Approvals
Absolute Maximum Ratings
• For ratings of individual members of a series, see Device Ratings and Specifications chart
Agency Agency File Number
E320116
Continuous
SM20 Series Units
Steady State Applied Voltage:
AC Voltage Range (V
M(AC)RMS
) 20 to 320 V
DC Voltage Range (V
M(DC)
)26V
Transients:
Peak Pulse Current (I
TM
) 8/20μs Current Wave, Single Pulse up to 6500 A
Single Pulse Energy Capability (W
TM
) 10/1000μs Current Wave 165 J
Load Dump Energy Capability (td>=30ms) 160 J
Operating Ambient Temperature Range (T
A
) -40 to +85
O
C
Storage Temperature Range (T
STG
) -55 to +125
O
C
Temperature Coefficient (a
V
) of Clamping Voltage (V
C
) at Specified Test Current <0.01 %/
O
C
Hi-Pot Encapsulation (COATING Isolation Voltage Capability)
(Dielectric must withstand indicated DC voltage for one minute per MIL-STD 202, Method 301)
2500 V
COATING Insulation Resistance 1000 MΩ
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only
rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is
not implied.
SM20 Varistor Series
Varistor Products
©2010 Littelfuse, Inc.
Revision: May 11, 2010
SM20 Series Varistor
Surface Mount Varistors > SM20 Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/sm20.html for current information.
Repetitive Surge Capability
V175SM20 - V320SM20
10,000
2,000
200
100
50
20
10
5
2
500
20 100 1,000 10,000
IMPULSE DURATION (μs)
SURGE CURRENT (A)
1
2
10
4
10
5
10
6
MODEL SIZE 20mm
V175SM20 - V320SM20
10
3
INDEFINITE
1,000
10
2
10
5,000
1
For applications exceeding 85ºC ambient temperature, the peak
surge current and energy ratings must be reduced as shown below
Peak Pulse Current Test Waveform for Clamping Voltage
Peak Current, Energy and Power Derating Curve
0
1
= Virtual Origin of Wave
T = Time from 10% to 90% of Peak
T
1
= Rise Time = 1.25 x T
T
2
= Decay Time
Example - For an 8/20 μs Current Waveform:
8μs = T
1
= Rise Time
20μs = T
2
= Decay Time
PERCENT OF PEAK VALUE Test
0
50
100
TIM E
t
1
t
t
O
1
100
90
80
70
60
50
40
30
20
10
0
-55 50 60 70 80 90 100 110 120 130 140 150
AMBIENT TEMPERATURE (
o
C)
PERCENT OF RATED VALUE
SM20 Series Ratings & Specifications
Maximum Rating (85°C) Specifications (25°C)
Continuous Transient
Varistor Voltage
at 1mA DC
Test Current
Maximum
Clamping
Voltage
8 x 20 μs
Typical
Capacitance
f = 1MHz
V
RMS
V
DC
Energy
10 x 1000μs
Peak Current
8 x 20μs
Part
Number
Branding
V
M(AC)
V
M(DC)
W
TM
1x pulse
I
TM
1x pulse
V
NOM
Min V
NOM
Max V
C
I
PK
C
(V) (V) (J) (A) (V) (V) (V) (A) (pF)
V26SM20 26SM20 20 26
20
160 (note 1)
2000
32
(10mA)
40
(10mA)
63 20 12000
V175SM20 175SM20 175 225 90 6500 247 303 455 100 1400
V230SM20 230SM20 230 300 122 6500 324 396 595 100 1100
V250SM20 250SM20 250 330 130 6500 354 429 650 100 1000
V275SM20 275SM20 275 369 140 6500 389 473 710 100 900
V300SM20 300SM20 300 405 165 6500 420 517 775 100 800
V320SM20 320SM20 320 420 150 6500 462 540 810 100 750
1. Energy rating for impulse duration of 30ms minimum to one half of peak current (automotive load dump).
Varistor Products
©2010 Littelfuse, Inc.
Revision: May 11, 2010
SM20 Series Varistor
Surface Mount Varistors > SM20 Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/sm20.html for current information.
SM20 Series
Lead (Pb) Soldering Recommendations
The principal techniques used for the soldering of
components in surface mount technology are IR Re-flow
and Wave soldering. Typical profiles are shown on the right.
The terminals of SM20 series devices are tin plated copper,
and the recommended solder is 62/36/2 (Sn/Pb/Ag), 60/40
(Sn/Pb) or 63/37 (Sn/Pb). Littelfuse also recommends an
RMA solder flux.
Wave soldering is the most strenuous of the processes.
To avoid the possibility of generating stresses due to
thermal shock, a preheat stage in the soldering process
is recommended, and the peak temperature of the solder
process should be rigidly controlled.
When using a reflow process, care should be taken to
ensure that the SM20 chip is not subjected to a thermal
gradient steeper than 4 degrees per second; the ideal
gradient being 2 degrees per second. During the soldering
process, preheating to within 100 degrees of the solder's
peak temperature is essential to minimize thermal shock.
Once the soldering process has been completed, it is
still necessary to ensure that any further thermal shocks
are avoided. One possible cause of thermal shock is hot
printed circuit boards being removed from the solder
process and subjected to cleaning solvents at room
temperature. The boards must be allowed to cool gradually
to less than 50ºC before cleaning.
Lead–free (Pb-free) Soldering Recommendations
The terminals of SM20 series devices are tin plated copper,
and the recommended Lead-free solder is 96.5/3.0/0.5
(SnAgCu) with an RMA flux, though there is a wide
selection of pastes and fluxes available that should be
compatible.
The reflow profile must be constrained by the maximums
in the Lead–free Reflow Profile. For Lead–free Wave
soldering, the Wave Solder Profile still applies.
Note: the Lead–free paste, flux and profile were used for
evaluation purposes by Littelfuse, based upon industry
standards and practices. There are multiple choices of all
three available, it is advised that the customer explores the
optimum combination for their process as processes vary
considerably from site to site.
PREHEAT ZONE
PREHEAT DWELL
RAMP RATE
<2°C/s
MAXIMUM TEMPERATURE
230°C
TEMPERATURE °C
TIME (MINUTES)
250
200
150
100
50
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
40-80
SECONDS
ABOVE 183°C
TIME (MINUTES)
300
250
200
150
100
50
0
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
MAXIMUM WAVE 260°C
SECOND PREHEAT
FIRST PREHEAT
TEMPERATURE °C
MAXIMUM TEMPERATURE 250˚C,
TIME WITHIN 5˚C OF PEAK
20 SECONDS MAXIMUM
PREHEAT ZONE
RAMP RATE
<3˚C/s
60 - 150 SEC
> 217˚C
TEMPERATURE °C
TIME (MINUTES)
300
250
200
150
100
50
0
0 1.0 2.0 3.0 4.0 5.0 6.0 7.0
Reflow Solder Profile
Wave Solder Profile
Lead–free Re-flow Solder Profile
P1-P3P4-P4

V300SM20

Mfr. #:
Buy V300SM20
Manufacturer:
Littelfuse
Description:
Varistors SURFACE MOUNT SM20 VARISTORS
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet