Littelfuse SM7 Varistor Series - Manual

© 2013 Littelfuse, Inc. 75
Revised: May 8, 2013
Varistor Products
SM7 Series Varistor
Surface Mount Varistors > SM7 Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/sm7.html for current information.
SM7 Series
RoHS
Description
The Littelfuse SM7 Series is a plastic-encapsulated
surface-mount metal oxide varistor (MOV) transient
voltage surge suppressor that is designed to be
operated continuously across AC power lines.
The series comprises a Nylon molded package with
tin plated lead frame for soldering to board. The
surface mount SM7 Series is based on radial 7mm
internal varistor element with similar characteristics
to the Littelfuse LA / ZA series of varistor.
Features
• Electrical equivalent
to leaded types
LA/ZA series
• AC Voltage Rating
115 to 510VAC rms
• No De-Rating up
to 85°C ambient
• Good solderability
• Available in tape
and reel
• Application of AC
power meters
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 SM7 Series Units
Steady State Applied Voltage:
AC Voltage Range (V
M(AC)RMS
) 115 to 510 V
DC Voltage Range (V
M(DC)
) 153 to 675 V
Transients:
Peak Pulse Current (I
TM
)
For 8/20μs Current Wave (See Figure 2) 1200 A
Single Pulse Energy Range
For 10/1000μs Current Wave (W
TM
) 10 to 40 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.
SM7 Varistor Series