Axial Lead & Cartridge Fuses PICO(R) ll > Very Fast-Acting Fuse > 251/253 Series 251/253 Series, PICO(R) II Very Fast-Acting Fuse PS E QPL Description The PICO(R) II Very Fast-Acting Fuse is designed to meet an extensive array of performance characteristics in a space-saving subminiature package. Features * Very fast-acting * Halogen-free available * Small size * Wide operating temperature range * Wide current rating range (0.062A- 15A) * Low temperature re-rating Applications Agency Approvals Secondary protection for space constrained applications Agency File Number Agency Ampere Range 253 Series PS E FM10 251 Series * Flat-panel display TV * Power supply * LCD monitor * Audio/Video system E10480 0.062A - 15A * LCD backlight inverter * Lighting system 29862 0.062A - 15A * Office machines * Medical equipment PSE_NBK200416-JP1021 1A - 5A J50158379 0.500A - 10A N/A 0.062A - 15A 2009010207366577 0.500A, 1A, 2A, 2.5A, 3A, 4A, 5A Electrical Characteristics for Series % of Ampere Rating Ampere Rating Opening Time 100% 0.062A - 15A 4 Hours, Min. 200% Note: See Electrical Specifications by Item table for specific approved ratings. 275% Additional Information 400% 1000% Datasheet 251 Series Resources 251 Series Samples 251 Series Datasheet 253 Series Resources 253 Series Samples 253 Series 0.062A - 7A 1 Second, Max. 10A 3 Seconds, Max. 12 - 15A 10 Seconds, Max. 0.500A, 1A, 2A, 2.5A, 3A, 4A, 5A, 7A, 10A 0.5A, 1A, 2A, 2.5A, 3A, 4A, 5A, 7A, 10A 0.500A, 1A, 2A, 2.5A, 3A, 4A, 5A, 7A, 10A 300 msecs., Max. 30 msecs., Max. 4 msecs., Max. (c) 2018 Littelfuse, Inc. Application testing is strongly recommended. Specifications are subject to change without notice. Revised: 05/31/18 Axial Lead & Cartridge Fuses PICO(R) ll > Very Fast-Acting Fuse > 251/253 Series Electrical Specifications by Item Agency Approvals Nom Max Nominal Ampere Nominal Ordering Ordering Voltage Amp Voltage Interrupting Cold Rating Melting Number Number Drop Code Rating Rating Resistance 2 (A) I t (A2 sec) (Std.) (Mil.) (V) (V) (Ohms) .062 .125 .200 .250 .375 .500 .630 .750 1.00 1.25 1.50 2.00 2.50 3.00 3.50 4.00 5.00 7.00 10.0 12.0 15.0 .062 .125 .200 .250 .375 .500 .630 .750 001. 1.25 01.5 002. 02.5 003. 03.5 004. 005. 007. 010. 012. 015. 251.062 251.125 251.200 251.250 251.375 251.500 251.630 251.750 251001. 2511.25 25101.5 251002. 25102.5 251003. 25103.5 251004. 251005. 251007. 251010. 251012. 251015. 253.062 253.125 253.200 253.250 253.375 253.500 253.750 253001. 25301.5 253002. 253003. 253004. 253005. 253007. 253010. 253015. 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 125 32 32 7.000 1.700 0.895 0.665 0.395 0.302 0.205 0.175 0.128 300 A @ 0.100 125VDC 0.0823 0.0473 50A@125VAC 0.0360 0.0295 0.0240 0.0204 0.0158 0.0107 0.0072 300A@32VDC0.0059 & 50A@32VAC 0.00446 0.000113 0.00174 0.0048 0.0116 0.0296 0.0598 0.08 0.153 0.256 0.390 0.587 0.405 0.721 1.19 1.58 2.45 4.14 10.4 25.5 45.2 68.8 1.4 0.285 0.345 0.24 0.215 0.2165 0.188 0.176 0.194 0.2 0.21 0.141 0.132 0.131 0.1205 0.114 0.11 0.102 0.1 0.0878 0.071 x x x x x x x x x x x x x x x x x x x x x Note: Higher ampere ratings are available. Please contact Littelfuse Technical Support or your Littelfuse products representative for assistance. (c) 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 05/31/18 QPL PS E x x x x x x x x x x x x x x x x x x x x x 253 Series Only x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x Axial Lead & Cartridge Fuses PICO(R) ll > Very Fast-Acting Fuse > 251/253 Series .250A .375A .500A .630A .750A 1A 1.25A 1.5A 2A 2.5A 3A 3.5A 4A 5A 7A 10A 12A 15A 100 .125A Average Time Current Curves .062A Temperature Re-rating Curve TIME IN SECONDS 10 1 0.1 Note: 1. Re-rating depicted in this curve is in addition to the standard derating of 25% for continuous operation. 0.01 Soldering Parameters Recommended Process Parameters: Wave Parameter Lead-Free Recommendation for 251 Series only 0.001 0.05 0.1 1 10 100 1000 CURRENT IN AMPERES Preheat: (Depends on Flux Activation Temperature) (Typical Industry Recommendation) Temperature Minimum: 100C Temperature Maximum: Preheat Time: 150C 60-180 seconds Solder Pot Temperature: 260C Maximum Solder Dwell Time: 2-5 seconds Recommended Hand Soldering Parameters: Solder Iron Temperature: 350C +/- 5C Heating Time: 5 seconds max. Note: These devices are not recommended for IR or Convection Reflow process (c) 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 05/31/18 Axial Lead & Cartridge Fuses PICO(R) ll > Very Fast-Acting Fuse > 251/253 Series Product Characteristics Materials Encapsulated, Epoxy-coated Body 251 Series: Pure tin-coated copper wire leads 253 Series: Solder-coated copper wire leads Solderability MIL-STD-202, Method 208 Lead Pull Force MIL-STD-202, Method 211, Test Condition A (will withstand a 7lbs. axial pull test) Fuses To MIL SPEC For fuses to MIL-PRF-23419, FM10 change the series number from 251 to 253 Operating Temperature -55C to +125C (Consider re-rating) Vibration MIL-STD-202, Method 201 (10-55 Hz); Method 204, Test Condition C (55-2000 Hz at 10 G's Peak) Shock MIL-STD-202, Method 213, Test Condition I (100 G's peak for 6 msecs.) Insulation Resistance (After Opening): MIL-STD-202, Method 302, Test Condition A (10,000 ohms minimum at 100 volts) Moisture Resistance MIL-STD-202, Method 106 Resistance to Soldering Heat Withstands 60 seconds above 200OC and up to 260C, maximum Flammability Rating UL 94V-0 Part Numbering System Dimensions 251 Series Markings (T1 lead length) 62.7 (2.468") 52.4 (2.062")* 27.78 (1.094") 7.11 (.280") LF 1A 6.35 (.25") tape 5.0 (.197") 0251 xxxx N R T1 L Series 251 = Standard type 253 = Military type 27.78 (1.094") Current Rating 2.80 (.11") MAX 6.35 (.25") tape Refer to Amp Code column of Electrical Specifications Table Quantity N = 5000 P = 2000 M = 1000 H = 100 LF 1A Wire Diameter: 0.64 (.025") for 0.062-10 amp, 0.81 (.032") for 12-15 amp Type of Packaging (T3 lead length) 83.31 (3.28") 38.1 (1.5") 73.0 (2.874")** 7.11 (.280") LF 6.35 (.25") tape LF Lead Length 2.61 (.103") MAX 6.35 (.25") tape Option Codes L = RoHS + HF (Only applies to 251 Series) 1A Wire Diameter: 0.64 (.025") for 0.062-10 amp, 0.81 (.032") for 15 amp 27.78 (T1 lead length) 62.7 (2.468") 52.4 (2.062")* The default lead length for Ammo pack(1.094") and Loose pack is now T1 for 251 series, and remains T3 for 253 series, therefore: T1 = 52.4mm (2.062"), 251 series only* Blank = 52.4mm (2.062") for(.25") 251 series* 5.0 (.197") 6.35 tape or 73mm (2.874") for 253 series** 38.1 (1.5") 1A 5.0 (.197") 251 Series (Halogen-free Version) Marki R = Reel A = Ammo Pack X = Loose Pack 253 Series Markings 7.11 (.280") LF 1A 1A LF 2.80 (.11") MAX Wire Diameter: 0.64 (.025") for 0.62-10.0 amp, 0.81 (.032") for 12-15 amp Packaging Packaging Option Packaging Specification *T1: 52.4mm (2.062") Tape and Reel EIA 296 **T3: 73mm (2.874') Tape and Reel EIA 296 Quantity & Packaging Code Please refer to available quantities above in "Part Numbering System" The default lead length for both ammo pack and loose pack is T1 for 251 and is T3 for 253. Notes: * T1 dimension is defined as the length of the component between the two tapes. The full component length is 62.7mm (2.468"). T1 length is for 251 series only. ** T3 dimension is defined as the length of the component between the two tapes. The full component length is 83.3.7mm (3.28"). T3 length is for 253 series only. 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. (c) 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 05/31/18 27.78 (1.094")