Surface Mount Fuses NANO2® > Slo-Blo® Fuse > 449 Series 449 Series Fuse RoHS Pb PS E Description The lead free NANO2® Slo-Blo® fuse is RoHS compliant, Halogen Free and 100% lead-free. This product is fully compatible with lead-free solder alloys and higher temperature profiles associated with lead-free assembly. The Slo-Blo® fuse design has enhanced inrush withstand characteristics over the NANO2® Fast-Acting Fuse. The unique time delay feature of this fuse design helps solve the problem of nuisance “opening” by accommodating inrush currents that normally cause a fast-acting fuse to open. Agency Approvals Features • Lead-free, Halogen free • Low temperature Agency Agency File Number Ampere Range and RoHS compliant rerating E10480 0.375A - 5A • Small size • UL Recognized to UL/CSA/ NMX UL 248-1 and UL/ PES NBK030205-E10480B 1A - 5A • Wide range of current CSA/NMX UL 248-14 ratings available • Conforms to DENAN’s • Wide operating Appendix 3 temperature range Electrical Characteristics for Series Applications Secondary protection for space constrained applications: % of Ampere Rating Opening Time • Notebook PC • Storage system 100% 4 hours, Minimum • LCD/PDP TV • Telecom system 200% 1 sec., Min.; 60 sec., Max. 300% 0.2 sec., Min.; 3 sec., Max • LCD monitor • Wireless basestation 800% 0.002 sec., Min.; 0.1 sec., Max. • LCD/PDP panel • White goods • LCD backlight inverter • Game console • Portable DVD player • Office Automation equipment • Power supply Additional Information • Battery charging circuit • Networking protection • PC server • Industrial equipment • Cooling fan system Datasheet Resources Samples Electrical Specifications by Item Max Nominal Cold Agency Approvals Ampere Rating Interrupting Nominal Melting Amp Code Voltage Rating Resistance (A) Rating I2t (A2sec) PS (V) (Ohms) E 0.375 .375 125 1.5130 0.088 x 0.500 .500 125 0.7633 0.258 x 0.750 .750 125 0.4080 0.847 x 1.00 001. 125 0.2516 1.76 x x 1.50 01.5 125 50A @125 VAC/VDC 0.1186 4.70 x x 2.00 002. 125 0.0708 6.76 x x 2.50 02.5 125 PSE: 100A @100 VAC 0.0400 13.18 x x 3.00 003. 125 0.0352 19.55 x x 3.50 03.5 125 0.0261 32.70 x x 4.00 004. 125 0.0227 40.80 x x 5.00 005. 125 0.0171 59.59 x x Notes - l2t calculated at 8ms. Resistance is measured at 10% of rated current, 25ºC © 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 11/21/19

Surface Mount Fuses NANO2® > Slo-Blo® Fuse > 449 Series Temperature Re-rating Curve Average Time Current Curves .375A.500A .750A1A 1.5A2A2.5A3A3.5A4A5A 1000 100 S 10 D N O C E S N E I M TI 1 Note: 1. Rerating depicted in this curve is in addition to the standard derating of 25% for continuous operation. 0.1 0.01 0 1 10 100 CURRENT IN AMPERES Soldering Parameters Reflow Condition Pb – Free assembly t P - Temperature Min (Ts(min)) 150°C TP Critical Zone Pre Heat - Temperature Max (Ts(max)) 200°C Ramp-up TL to TP - Time (Min to Max) (t) 60 – 180 secs T s L t Average ramp up rate (Liquidus Temp (TL) to peak 3°C/second max. eruTS(max) L T to T - Ramp-up Rate 3°C/second max. ta S(max) L r Ramp-down e - Temperature (T) (Liquidus) 217°C p Preheat Reflow L mTS(min) - Temperature (tL) 60 – 150 seconds eT tS Peak Temperature (T) 260+0/–5 °C P Time within 5°C of actual peak Temperature (t) 20 – 40 seconds 25 p time to peak temperature Ramp-down Rate 5°C/second max. (t 25ºC to peak) Time Time 25°C to peak Temperature (T) 8 minutes max. P Do not exceed 260°C Wave Soldering Parameters 260°C Peak Temperature, 3 seconds max. © 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 11/21/19

Surface Mount Fuses NANO2® > Slo-Blo® Fuse > 449 Series Product Characteristics Body: Ceramic MIL-STD-202, Method 107, Test Condition Materials Terminations: Gold-plated Caps Thermal Shock B, 5 cycles, -65°C to 125°C, 15 minutes @ Product Marking Brand, Amperage Rating each extreme MIL-STD-202, Method 213, Test I: Operating Temperature -55°C to 125°C Deenergized. 100G’s pk amplitude, Moisture Sensitivity Level Level 1, J-STD-020 Mechanical Shock sawtooth wave 6ms duration, 3 cycles Solderability MIL-STD-202, Method 208 XYZ+xyz = 18 shocks Insulation Resistance MIL-STD-202, Method 302, Test Condition A MIL-STD-202, Method 201: 0.03" (after Opening) (10,000 ohms minimum) Vibration amplitude, 10-55 Hz in 1 min. 2hrs each XYZ=6hrs Moisture Resistance MIL-STD-202, Method 106, 10 cycles MIL-STD-202, Method 101, Test Condition Salt Spray B (48hrs) MIL-STD-202, Method 210, Test condition Resistance to Soldering Heat B (10 sec at 260°C) Dimensions Part Numbering System 0449 001. M R 6.86 6.10 ± .20 (.270") (.240") Series 3.15 1 A AMP Code* (.124") F T Refer to Electrical characteristics table 1.45 2.95 (.057") Quantity Code 1.96 (.116") M = 1000 pcs (.077") 2.69 ± .25 Packaging Code Recommended pad layout (.106") R = Tape and Reel 2.69 ± .25 *Example: (.106") 0.375 Amp product is 0449.375MR (1 amp product shown above). Packaging Quantity & Packaging Option Packaging Specification Quantity Packaging Code 12mm Tape and Reel EIA RS-481-2 (IEC 286, part 3) 1000 MR Disclaimer Notice - Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. 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: 11/21/19