Varistor Products
Surface Mount Varistors > SM20 Series
SM20 Varistor 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.
Agency Approvals
Features
Agency
Agency File Number
•
•
•
•
DC Voltage
Rating 26VDC
•
•
Low voltage
E320116
devices specified
for automotive load
dump energy
AC Voltage Rating
175 - 320AC
Available in "waffle"
tray packaging
No De-Rating up
to 85°C ambient
Lead-Free, Halogen-
Free and RoHS
Compliant
Absolute Maximum Ratings
• For ratings of individual members of a series, see Device Ratings and Specifications chart
Continuous
SM20 Series
Units
Steady State Applied Voltage:
AC Voltage Range (VM(AC)RMS
)
20 to 320
26
V
V
DC Voltage Range (VM(DC)
)
Transients:
Peak Pulse Current (ITM) 8/20μs Current Wave, Single Pulse
Single Pulse Energy Capability (WTM)10/1000μs Current Wave
Load Dump Energy Capability (td>=30ms)
up to 6500
165
A
J
160
J
Operating AmbientTemperature Range (TA)
-40 to +85
-55 to +125
<0.01
OC
OC
%/OC
StorageTemperature Range (TSTG
)
Temperature Coefficient (aV) of Clamping Voltage (VC) at SpecifiedTest Current
Hi-Pot Encapsulation (COATING Isolation Voltage Capability)
(Dielectric must withstand indicated DC voltage for one minute per MIL-STD 202, Method 301)
COATING Insulation Resistance
2500
V
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.
©2010 Littelfuse, Inc.
SM20 SeriesVaristor
Specifications are subject to change without notice.
Revision: May 11, 2010
Please refer to www.littelfuse.com/series/sm20.html for current information.