Surface Mount Fuses Thin Film > 0603 Size > Fast-Acting > 494 Series 494 Series Fuse, NRA Special Series Integrated Circuit Protector RoHS Pb ® Description The 494 Series Fast-Acting SMF is an ultra small (0603 size) thin-film device designed for secondary protection of circuits used in space constrained applications such as hand-held portable electronic devices. This series is 100% lead-free and meets the requirements of the RoHS directive. New Halide-Free 494 Series fuses are available to order using the “HF” suffix. See Part Numbering section for additional information. Features Agency Approvals • Compatible with lead- • Element-covering material free solders and higher is resistant to industry Agency Agency File number Ampere rAnge temperature profiles standard cleaning • High performance operations e10480 250mA - 5A ® materials provide • Mounting pad and improved performance electrical performance are lr29862 250mA - 5A in elevated ambient identical to Littelfuse 431 temperature applications and 434 Series products Electrical Characteristics for Series • Marked on top surface • Alloy-based element with code to allow ampere construction provides % of Ampere Opening Time at 25Oc rating identification superior inrush withstand rating without testing characteristics (I2t) over 100% 4 hours, Minimum • Low profile for height ceramic or glass-based 200% 5 sec., Maximum sensitive applications 0603 fuse products 300% 0.2 sec., Maximum • Flat top surface for pick- and-place operations Additional Information Applications Secondary protection for space constrained applications: • Cell phones • Digital cameras • Hard disk Datasheet Resources Samples • Battery packs • DVD players drives Electrical Specifications by Item max nom nom Agency Approvals Ampere nominal cold nominal Amp Voltage interrupting Voltage power rating resistance melting code rating rating Drop Dissipation (A) (V) (Ohms) i2t (A2sec) (mV) (W) ® 0.250 .250 32 0.5450 0.0030 158.56 0.0396 x x 0.375 .375 32 0.2900 0.0053 128.03 0.0480 x x 0.500 .500 32 50A @32V AC/DC 0.1870 0.0087 115.71 0.0579 x x 0.750 .750 32 0.1170 0.0171 107.33 0.0805 x x 1.00 001. 32 0.0710 0.0212 89.10 0.0891 x x 1.25 1.25 32 0.0530 0.0518 84.32 0.1054 x x 1.40 01.4 32 0.049 0.05529 74.84 0.1048 x x 1.50 01.5 32 0.0410 0.0766 81.14 0.1217 x x 1.75 1.75 32 0.0320 0.0903 78.75 0.1378 x x 2.00 002. 32 0.0300 0.1103 78.22 0.1564 x x 2.50 02.5 32 35A @32V AC/DC 0.0220 0.1440 76.10 0.1903 x x 3.00 003. 32 0.0180 0.2403 75.04 0.2251 x x 3.15 3.15 32 0.017 0.27405 63.78 0.2009 x x 3.50 03.5 32 0.0150 0.4306 74.25 0.2599 x x 4.00 004. 32 0.0130 0.5760 73.72 0.2949 x x 5.00 005. 32 0.0090 0.9000 72.71 0.3635 x x 1. Measured at 10% of rated current, 25ºC. 2. Measured at rated voltage. © 2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 10/25/14

Surface Mount Fuses Thin Film > 0603 Size > Fast-Acting > 494 Series Temperature Rerating Curve Average Time Current Curves A AA A 0.250 0.375 0.500 0.750 1.00 A1.25 A1.50 A 1.75 A2.00 A2.50 A3.00 A3.50 A4.00 A5.00 A 100 10 S D N O C SE1 N E I M TI 0.1 0.01 0.001 0.1 1 10 100 CURRENT IN AMPERES Soldering Parameters reflow condition Pb – free assembly t P T P Critical Zone - Temperature min (T ) 150°C Ramp-up TL to TP s(min) pre Heat -- TTeimmep e(mraitnu rteo mmaaxx )( T(tss()max)) 2600 0–° C180 seconds erutaTS(mTaxL) tL Average ramp-up rate (liquidus Temp r Ramp-down (Tl) to peak) 5°C/second max. epmTS(min) Preheat T to T - ramp-up rate 5°C/second max. eT tS S(max) l - Temperature (T) (liquidus) 217°C reflow l 25 - Temperature (t) 60 – 150 seconds time to peak temperature l Time (t 25ºC to peak) peak Temperature (T ) 250+0/-5 °C p Time within 5°c of actual peak 20 – 40 seconds Temperature (t ) p ramp-down rate 5°C/second max. Time 25°c to peak Temperature (T ) 8 minutes max. p Do not exceed 260°C © 2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 10/25/14

Surface Mount Fuses Thin Film > 0603 Size > Fast-Acting > 494 Series Product Characteristics Body: Advanced High Temperature Substrate Thermal Shock Withstands 5 cycles of – 55°C to 125°C Materials Terminations: 100% Tin over Nickel over Copper Vibration Per MIL-STD-202F Element Cover Coat: Conformal Coating Insulation Resistance – 55°C to 90°C. Consult temperature rerating Greater than 10,000 ohms Operating (After Opening) curve chart. For operation above 90°C contact Temperature Littelfuse. Resistance to Withstands 60 seconds above 200°C Soldering Heat and up to 260°C, maximum Humidity MIL-STD-202F, Method 103B, Condition D Dimensions Part Marking System 1.60 Amp marking (.063") .305 code code .127 (.012") (.005") .250 D Sn .375 E .500 F .279 Coating .750 G (.011") MARKING CODE VARIES 001. H Sn WITH AMPERAGE RATING Cu (SEE CHART) 1.25 J .18 .813 R (.007") 01.4 (.032") REF. 01.5 K Sn 1.75 L 1.09 (.043") 002. N 02.5 O 1.02 3.20 (.040") (.126") 2.54 1.02 003. P (.100") (.040") .762 3.15 (.030") 03.5 R 1.09 1.09 (.043") (.043") 004. S WAVE SOLDER REFLOW SOLDER 005. T Packaging Part Numbering System 0494002.NRHF Quantity & packaging packaging Quantity packaging Option Specification SERIES code AMP Code 8mm Tape EIA RS-481-2 (IEC 5000 NR Refer to Amp Code column in the and Reel 286, part 3) Electrical Specifications table. NOTE: The dot is poisitioned before the Packaging Suffix with whole ratings and within the numbering sequence for fractional ratings. PACKAGING Code NR = Tape and Reel, 5000 pcs ‘HF’ SUFFIX HALIDE FREE ITEM © 2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 10/25/14