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 plugin 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 % of Ampere Rating Ampere Rating Opening Time QPL-23419 0.002A - 5A QPL 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 2 2 Rating I t (A sec) QPL (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. Specifications are subject to change without notice. Application testing is strongly recommended. Revised: 11/14/19Axial Lead & Cartridge Fuses MICRO > Very Fast-Acting Fuse > 272/273/274/278/279 Series Temperature Re-rating Curve Average Time Current Curves 100 10 1 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: 300 280 Wave Parameter Lead-Free Recommendation 260 240 Preheat: 220 (Depends on Flux Activation Temperature) (Typical Industry Recommendation) 200 180 Temperature Minimum: 100 C 160 Temperature Maximum: 150 C 140 Preheat Time: 60-180 seconds 120 100 Solder Pot Temperature: 260 C Maximum 80 60 Solder Dwell Time: 2-5 seconds 40 Recommended Hand-Solder Parameters: 20 Solder Iron Temperature: 350 C +/- 5C 0 Heating Time: 5 seconds max. Note: These devices are not recommended 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 Temperature (C) - Measured on bottom side of board 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 TIME IN SECONDS 1/200 A 1/100 A 1/64 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