Revised: January 7, 2009
131
© 2009 Littelfuse, Inc.
Specifications are subject to change without notice.
Radial Lead Fuses
272/273/274/278/279 Series
Please refer to www.littelfuse.com/series/272.html, /273.html, /274.html,
/278.html or /279.html for current information.
MICRO™ > Very Fast-Acting > 272/273/274/278/279 Series
272-4/278-9
272/273/274/278/279 Series, MICRO™ Very Fast-Acting Fuse
Description
Developed originally for the U.S. Space Program,
MICRO™ fuse provides reliability in a compact design.
The MICRO™ fuse is available in plug–in or radial lead
styles and a complete range of ampere ratings from
1/500 to 5A to suit a wide variety of design needs.
Agency Approvals
Agency Agency File Number Ampere Range
E10480 2mA - 5A
LR 29862 2mA - 5A
QP
FM02 2mA - 5A
Features
Electrical Characteristics
Applications
QPL
% of Ampere
Rating
Ampere Rating Opening Time
100% 1/500–5 4 Hours, Min.
200%
1/500–3/10 5 Seconds, Max.
4/10-5 2 Seconds, Max.
Ampere
Rating
(A)
Amp Code
(for all
above
series)
Max
Voltage
Rating
(V)
Interrupting
Rating
Nominal
Cold
Resistance
(Ohms)
Nominal
Melting
I
2
t (A
2
sec)
Agency Approvals
QP
.002 .002 125
10,000 amperes at
125 VAC/VDC.
2200 0.00000000845
XXX
.005 .005 125 280 0.00000000810
XXX
.010 .010 125 80.0 0.000000462
XXX
.015 .015 125 44.0 0.00000123
XXX
.031 .031 125 16.0 0.00000810
XXX
.050 .050 125 3.20 0.0000666
XXX
.062 .062 125 2.32 0.000115
XXX
.100 .100 125 1.25 0.000385
XXX
.125 .125 125 1.0 0.000691
XXX
.200 .200 125 2.30 0.00409
XXX
.250 .250 125 1.75 0.00640
XXX
.300 .300 125 1.25 0.00945
XXX
.400 .400 125 0.227 0.0251
XXX
.500 .500 125 0.167 0.0716
XXX
.600 .600 125 0.430 0.0411
XXX
.700 .700 125 0.324 0.0710
XXX
.750 .750 125 0.293 0.0900
XXX
.800 .800 125 0.271 0.113
XXX
1.00 001. 125 0.0880 0.0648
XXX
01.5 01.5 125 0.0578 0.160
XXX
2.00 002. 125 0.0425 0.300
XXX
3.00 003. 125 0.0275 0.759
XXX
4.00 004. 125 0.0202 1.38
XXX
5.00 005. 125 0.0156 2.21
XXX
Electrical Characteristics
Military grade availablet
High breaking capacityt
Clear cover option to view t
fuse element status
Available from very low t
ampere of 2mA to 5A
Plug-in with short or long t
leads option
Printed circuit boards t
and similar equipment
Electronic componentst