0438.750WR Littelfuse

Surface Mount Fuses Ceramic Fuse > 438 Series RoHS Pb 438 Series 0603 Fast-Acting Fuse HF Description The 438 Series is a 100% Lead-free, RoHS compliant and Halogen-free fuse series designed specifically to provide over-current protection to circuits that operate under high working ambient temperature up to 150C. The general design ensures excellent temperature stability and performance reliability. The high It values which is typical in the Littelfuse Ceramic Fuse family ensure high inrush current withstand capability. Features Operating Temperature Suitable for both leaded from -55C to +150C and lead-free reflow / Agency Approvals wave soldering 100% Lead-free, RoHS Agency Agency File Number Ampere Range compliant and Halogen- Recognized to UL/CSA/ free NMX 248-1 and UL/CSA/ E10480 0.250A 6A NMX 248-14 29862 0.250A 6A Applications Handheld Electronics Hard Disk Drives LCD Displays SD Memory Cards Electrical Characteristics for Series Battery Packs % of Ampere Ampere Rating Opening Time at 25C Additional Information Rating 100% 0.25A 6A 4 Hours, Minimum 250% 0.25A 6A 5 Seconds, Maximum Datasheet Resources Samples Electrical Specifications by Item Ampere Max. Nominal Nominal Nominal Voltage Nominal Power Agency Approvals Amp 2 Rating Voltage Interrupting Rating Resistance Melting I t Drop At Rated Dissipation At Rated Code 2 2 3 4 (A) Rating (V) (Ohms) (A Sec.) Current (V) Current (W) 0.250 .250 63VDC 2.218 0.0017 0.550 0.138 x x 0.375 .375 63VDC 1.247 0.0041 0.488 0.183 x x 0.500 .500 63VDC 0.829 0.0100 0.486 0.243 x x 0.750 .750 63VDC 0.466 0.0281 0.378 0.284 x x 50A 63VDC 50A 32VAC 1.00 001. 63VDC 0.310 0.0593 0.351 0.351 x x 1.25 1.25 63VDC 0.200 0.0510 0.365 0.456 x x 1.50 01.5 63VDC 0.174 0.0902 0.368 0.552 x x 1.75 1.75 63VDC 0.1405 0.1440 0.360 0.540 x x 2.00 002. 32 0.051 0.1490 0.107 0.214 x x 2.50 02.5 32 0.0324 0.1977 0.095 0.238 x x 3.00 003. 32 0.0255 0.2922 0.093 0.279 x x 50A 32VDC/12VAC 3.50 03.5 32 0.0205 0.4752 0.082 0.287 x x 4.00 004. 32 0.0170 0.6920 0.079 0.316 x x 5.00 005. 32 0.0115 0.7398 0.074 0.370 x x 6.00 006. 24 50A 24VDC/12VAC 0.0085 1.3838 0.072 0.432 x x Notes: 1. AC Interrupting Rating tested at rated voltage with unity power factor. DC Interrupting Rating tested at rated 4. Nominal Voltage Drop measured at rated current after temperature has stabilized. voltage with time constant < 0.8 msec. Devices designed to carry rated current for 4 hours minimum. It is recommended that devices be operated 2. Nominal Resistance measured with < 10% rated current. continuously at no more than 80% rated current. See Temperature Re-rating Curvefor additional re-rating 3. Nominal Melting It measured at 1 msec. opening time. information. Devices designed to be mounted with marking code facing up. 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 10/11/19Surface Mount Fuses Ceramic Fuse > 438 Series Temperature Re-rating Curve Average Time Current Curves 140 100 120 100 10 80 60 1 40 -65 -45 -25 -5 15 35 55 75 95 115 135 155 TEMPERATURE (C) 0.1 Note: 1. Re-rating depicted in this curve is in addition to the standard re-rating of 20% for continuous operation. Example: For continuous operation at 75 degrees celsius, the fuse should be rerated as follows: 0.01 I = (0.80)(0.85)I = (0.68)I RAT RAT 0.001 0.1 1 10 100 CURRENT IN AMPERES Soldering Parameters Reflow Condition Pb free assembly t P - Temperature Min (T ) 150C s(min) T P Critical Zone Pre Heat - Temperature Max (T ) 200C Ramp-up s(max) T to T L P - Time (Min to Max) (t ) 60 180 seconds s T L Average Ramp-up Rate (Liquidus Temp (T ) to peak) 3C/second max. L t L T S(max) T to T - Ramp-up Rate 5C/second max. S(max) L - Temperature (T ) (Liquidus) 217C L Ramp-down Reflow - Temperature (t ) 60 150 seconds Preheat L T +0/-5 S(min) Peak Temperature (T ) 260 C P t S Time within 5C of actual peak Temperature (t ) 10 30 seconds p Ramp-down Rate 6C/second max. 25 Time 25C to peak Temperature (T ) 8 minutes max. P time to peak temperature Time Do not exceed 260C (t 25C to peak) Wave Soldering 260C, 10 seconds max. 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 10/11/19 PERCENT OF RATING TIME IN SECONDS .250A .375A .500A .750A 1A 1.25A 1.5A 1.75A 2A 2.5A 3A 3.5A 4A 5A 6A Temperature