Subminiature
Axial Lead and Cartridge Fuses
MICRO™FUSE Very Fast-Acting Type 272/273/274/278/279 Series
392 www.littelfuse.com
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
5 amperes to suit a wide variety of design needs.
ELECTRICAL CHARACTERISTICS:
% of Ampere Ampere Opening
Rating Rating Time
100% 1/500–5 4 hours, Minimum
200% 1/500–3/10 5 seconds, Maximum
4/10–5 2 seconds, Maximum
AGENCY APPROVALS: Recognized under the Components Program
of Underwriters Laboratories and Certified by CSA.
AGENCY FILE NUMBERS: UL E10480, CSA LR 29862.
INTERRUPTING RATING: 10,000 amperes at 125 VAC/VDC.
FUSES TO MIL SPEC: 273 Series is available in Military QPL type
(FM02). To order, change 273 to 274.
Operating Temperature:
273 and 279: –55°C to 85°C.
272 and 278: –55°C to 125°C
PATENTED
ORDERING INFORMATION:
Plug-In Radial Lead
Nominal Nominal
Catalog Catalog Catalog Catalog Ampere Voltage Resistance Melting I2t
Number Number Number Number Rating Rating Cold Ohms A2Sec.
272.002 273.002 278.002 279.002 1/500 125 2200 0.00000000845
272.005 273.005 278.005 279.005 1/200 125 280 0. 0.0000000810
272.010 273.010 278.010 279.010 1/100 125 80.0 0.000000462
272.015 273.015 278.015 279.015 1/64 125 44.0 0.00000123
272.031 273.031 278.031 279.031 1/32 125 16.0 0.00000810
272.050 273.050 278.050 279.050 1/20 125 3.20 0.0000666
272.062 273.062 278.062 279.062 1/16 125 2.32 0.000115
272.100 273.100 278.100 279.100 1/10 125 1.25 0.000385
272.125 273.125 278.125 279.125 1/8 125 1.0 0.000691
272.200 273.200 278.200 279.200 2/10 125 2.30 0.00409
272.250 273.250 278.250 279.250 1/4 125 1.75 0.00640
272.300 273.300 278.300 279.300 3/10 125 1.25 0.00945
272.400 273.400 278.400 279.400 4/10 125 0.227 0.0251
272.500 273.500 278.500 279.500 1/2 125 0.167 0.0716
272.600 273.600 278.600 279.600 6/10 125 0.430 0.0411
272.700 273.700 278.700 279.700 7/10 125 0.324 0.0710
272.750 273.750 278.750 279.750 3/4 125 0.293 0.0900
272.800 273.800 278.800 279.800 8/10 125 0.271 0.113
272 001 273 001 278 001 279 001 1 125 0.0880 0.0648
272 01.5 273 01.5 278 01.5 279 01.5 11/2125 0.0578 0.160
272 002 273 002 278 002 279 002 2 125 0.0425 0.300
272 003 273 003 278 003 279 003 3 125 0.0275 0.759
272 004 273 004 278 004 279 004 4 125 0.0202 1.38
272 005 273 005 278 005 279 005 5 125 0.0156 2.21
100
10
1
0.1
0.01
0.001
110 100
0.01 0.1
0.005
1/64 A
1/100 A
1/200 A
1/32 A
1/16 A
1/8 A
1/4 A
1/2 A
3/4 A
1 A
1 1/2 A
2 A
3 A
4 A
5 A
TIME IN SECONDS
CURRENT IN AMPERES
Average Time Current Curves
7.30
(.29") (.17")
8.89
(.35")
2.54 (.10")
7.30
(.29") 25.4 (1.0")
2.54 (.10")
25.4 (1.0")
2.54 (.10")
5.97
(.235") 6.35
(.25")
5.97
(.235")
2.54 (.10")
8.89
(.35")
6.35
(.25")
272 000 Series 273 000 Series
278 000 Series
279 000 Series
NOTE: Amperage and voltage rating stamped on cap. Leads are solder-coated
copper; .025" diameter.
(.17")
4.32 4.32
®QPL
®
