Axial Lead & Cartridge Fuses MICRO™ > Very Fast-Acting Fuse > 272/273/274/278/279 Series 272/273/274/278/279 Series, MICRO™ Very Fast-Acting Fuse QPL 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 0.002A to 5A to suit a wide variety of design needs. Features • Military grade available • Plug-in with short or long leads option • High breaking capacity • Recognized to UL/CSA/ • Clear cover option to view NMX 248-1 and UL/CSA/ fuse element status NMX 248-14 • Available from very low ampere of 0.002A to 5A Agency Approvals Applications • Printed circuit boards • Electronic components Agency Agency File Number Ampere Range and similar equipment E10480 0.002A - 5A Electrical Characteristics 29862 0.002A - 5A QPL QPL-23419 0.002A - 5A % of Ampere Rating Ampere Rating Opening Time 100% 0.002 – 5 4 Hours, Min. 0.002 – 0.3 5 Seconds, Max. 200% 0.4 - 5 2 Seconds, Max. Electrical Characteristics Agency Approvals Ampere Amp Code Max Nominal Cold Interrupting Nominal Melting Rating (for all above Voltage Resistance QPL Rating I2t (A2 sec) (A) series) Rating (V) (Ohms) 0.002 0.002 125 2200 0.00000000845 X X X 0.005 0.005 125 280 0.0000000766 X X X 0.010 0.010 125 80.0 0.000000462 X X X 0.015 0.015 125 44.0 0.00000123 X X X 0.031 0.031 125 16.0 0.00000810 X X X 0.050 0.050 125 3.52 0.0000666 X X X 0.062 0.062 125 2.55 0.000115 X X X 0.100 0.100 125 1.38 0.000385 X X X 0.125 0.125 125 1.0 0.000691 X X X 0.200 0.200 125 2.30 0.00409 X X X 0.250 0.250 125 1.75 0.00640 X X X 0.300 0.300 125 1.25 0.00945 X X X 10,000A@125VAC/VDC 0.400 0.400 125 0.227 0.0251 X X X 0.500 0.500 125 0.167 0.0716 X X X 0.600 0.600 125 0.430 0.0411 X X X 0.700 0.700 125 0.324 0.0710 X X X 0.750 0.750 125 0.293 0.0563 X X X 0.800 0.800 125 0.271 0.113 X X X 1.00 001.0 125 0.0880 0.0648 X X X 01.5 01.5 125 0.0578 0.160 X X X 2.00 002.0 125 0.0425 0.300 X X X 3.00 003.0 125 0.0275 0.759 X X X *4.00 004.0 125 0.0202 1.38 X X X *5.00 005.0 125 0.0156 2.21 X X X * The fuses of 4A and 5A for 272 and 278 Series are obsolete. © 2019 Littelfuse, Inc. Specifications are subject to change without notice. ASpppelcicifiactiaotnio tness tainreg sisu bstjerocnt gtoly c rheacnogmem weinthdoeudt. notice. Revised: 11/14/19

Axial Lead & Cartridge Fuses MICRO™ > Very Fast-Acting Fuse > 272/273/274/278/279 Series Temperature Re-rating Curve Average Time Current Curves 1/200 A 1/100 A1/64 A 1/32 A 1/16 A 1/8 A 1/4 A 1/2 A3/4 A1 A1 1/2 A2 A3 A4 A5 A 100 10 S D N O C 1 E S N E I M TI 0.1 Note: 1. Rerating depicted in this curve is in addition to the standard derating of 25% for 0.01 continuous operation. 0.001 0.005 0.01 0.1 1 10 100 CURRENT IN AMPERES Soldering Parameters - Wave Soldering Recommended Process Parameters: 300 Measured on bottom side of board 111112222202468024680000000000 P( D r eeTTPpeehremmeenhadppestee: aorrtWaan Ttt Fuuaimlrrvueexee MMA:Pcaiatnirxviaamimmtiouuenmm tTee::rmperature) (116T050yp00-1i°°Lc8 aeCC0l aI nsdde-uFcsroternyed RsReeccomommemndeantidoan)tion C) - 80 Solder Pot Temperature: 260° C Maximum mperature (° 246000 RSeScooollmddemer eIrrno Dnd eTwdem eHpaleln rTadt-iuSmroe:le d3:e5r0 °P Ca r+a/m- 5e°tCe rs: 2-5 seconds Te 00 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 NoHtee:a Ttihnegs Tei mdeev: i5ce sse acoren dnso tm raexc.ommended for IR or Convection Reflow process. Time (Seconds) Preheat Time Cooling Time Dwell Time © 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 11/14/19

Axial Lead & Cartridge Fuses MICRO™ > Very Fast-Acting Fuse > 272/273/274/278/279 Series Product Characteristics Dimensions 273 and 279: –55ºC to +85ºC; 272 000 Series Operating Temperature: 272 and 278: –55ºC to +125ºC (Short Lead, Metal Cap) Military QPL type (FM02). Fuses to MIL SPEC 5.97 7.30 To order, change 273 to 274. (.235") (.29") 4.32 272 and 278 series cap: (.17") Nickel Plated Brass 2.54 (.10") 273, 274 and 279 series cap: Materials Mirror polished Polycarbonate Base: R-4 Ryton 278 000 Series (Long Lead, Metal Cap) Pins: Tin Plated Copper 5.97 7.30 Product Marking Current and voltage ratings stamped on cap (.235") (.29") 25.4 (1.0") 2.54 (.10") Part Numbering System 273 000 and 274 000 Series 0273 xxxx V (Short Lead, Clear Plastic Cap) 6.35 8.89 Series (.25") (.35") 4.32 (.17") Amp. Code Refer to Amp Code column of 2.54 (.10") Electrical Characteristics Table Packaging Code V = 5 279 000 Series H = 100 (Long Lead, Clear Plastic Cap) 6.35 Additional Information (.25") 8.89 (.35") 25.4 (1.0") 2.54 (.10") Datasheet Resources Samples NOTE: Amperage and voltage rating stamped on cap. 272 Series 272 Series 272 Series Leads are tin plated copper; .025" diameter. Packaging Datasheet Resources Samples Packaging Packaging Quantity & Quantity 273 Series 273 Series 273 Series Option Specification Packaging Code Bulk N / A 5 V Bulk N / A 100 H *Only V-pack version for low current rating from 0.002 - 0.062 (A) and for 274, 278, 279 Series Datasheet Resources Samples 274 Series 274 Series 274 Series Datasheet Resources Samples 278 Series 278 Series 278 Series Datasheet Resources Samples 279 Series 279 Series 279 Series Disclaimer Notice - Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at: www.littelfuse.com/disclaimer-electronics. © 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 11/14/19