1 ? 2009 littelfuse, inc. specifcations are subject to change without notice. surface mount fuses 438 series ceramic fuse > 438 series please refer to www.littelfuse.com/series/438.html for current information. 438 series 438 series C 0603 fast-acting fuse description the 438 series is a 100% lead-free, rohs compliant and halogen-free fuse series designed specifcally to provide over-current protection to circuits that operate under high working ambient temperature up to 150oc. the general design ensures excellent temperature stability and performance reliability. the high i2t values which is typical in the littelfuse ceramic fuse family ensure high inrush current withstand capability. agency approvals agency agency file number ampere range e10480 0.250a C 6a lr29862 0.250a C 6a features electrical characteristics for series ? operating temperature from -55oc to +150oc ? 100% lead-free, rohs compliant and halogen- free ? suitable for both leaded and lead-free refow / wave soldering % of ampere rating ampere rating opening time at 25oc 100% 0.250a C 6a 4 hours, minimum 250% 0.250a C 6a 5 seconds, maximum applications ampere rating (a) amp code max. voltage rating (v) interrupting rating nominal resistance (ohms) 2 nominal melting i 2 t (a 2 sec.) 3 nominal voltage drop at rated current (v) 4 nominal power dissipation at rated current (w) agency approvals 0.25 .250 63 50a @ 63vdc 50a @ 32vac 2.024 0.0017 0.550 0.138 x x 0.375 .375 63 1.247 0.0041 0.488 0.183 x x 0.5 .500 63 0.829 0.0100 0.486 0.243 x x 0.75 .750 63 0.466 0.0281 0.378 0.284 x x 1 001. 63 0.310 0.0593 0.351 0.351 x x 1.25 1.25 63 0.200 0.0510 0.365 0.456 x x 1.5 01.5 63 0.174 0.0902 0.368 0.552 x x 1.75 1.75 63 0.125 0.1440 0.360 0.540 x x 2 002. 32 50a @ 32vdc/12vac 0.051 0.1490 0.107 0.214 x x 2.5 02.5 32 0.0324 0.1977 0.095 0.238 x x 3 003. 32 0.0252 0.2922 0.093 0.279 x x 3.5 03.5 32 0.0203 0.4752 0.082 0.287 x x 4 004. 32 0.0169 0.6920 0.079 0.316 x x 5 005. 32 0.0113 0.7398 0.074 0.370 x x 6 006. 24 50a @ 24vdc/12vac 0.0087 1.3838 0.072 0.432 x x electrical specifcations by item notes: 1. ac interrupting rating tested at rated voltage with unity power factor. dc interrupting rating tested at rated voltage with time constant < 0.8 msec. 2. nominal resistance measured with < 10% rated current. 3. nominal melting i2t measured at 1 msec. opening time. 4. nominal voltage drop measured at rated current after temperature has stabilized. ? handheld electronics ? lcd displays ? battery packs ? hard disk drives ? sd memory cards ? automotive electronics devices designed to carry rated current for 4 hours minimum. it is recommended that devices be operated continuously at no more than 80% rated current. see temperature rerating curvefor additional rerating information. devices designed to be mounted with marking code facing up. revised: february 15, 2012
introduction to circuit protection introduction to circuit protection transientology 2 ? 2009 littelfuse, inc. specifcations are subject to change without notice. surface mount fuses 438 series ceramic fuse > 438 series please refer to www.littelfuse.com/series/438.html for current information. average time current curves 0.001 0.01 0.1 1 10 100 .250a 4a 3.5a 3a 2.5a 2a 1.75a 1.5a 1.25a 1a .500a .375a 6a 5a .750a time i n s e c o n d s 0.1 1 1 0 1 0 0 c urr e n t i n amperes refow condition pb C free assembly pre heat - temperature min (t s(min) ) 150c - temperature max (t s(max) ) 200c - time (min to max) (t s ) 60 C 180 seconds average ramp-up rate (liquidus temp (t l ) to peak) 3csecond max. t s(max) to t l - ramp-up rate 5csecond max. refow - temperature (t l ) (liquidus) 21c - temperature (t l ) 60 C 150 seconds peak temperature (t p ) 260 0-5 c time within 5c of actual peak temperature (t p ) 10 C 30 seconds ramp-down rate 6csecond max. time 25c to peak temperature (t p ) 8 minutes max. do not exceed 260c soldering parameters temperature rerating curve 40 60 80 10 0 12 0 14 0 -6 5 -45 -25 -5 15 35 55 75 95 115 135 15 5 te m per at ur e ( c) pe rc en t of ra ti ng example: wave soldering 260c 10 seconds max. ti me te mperature t p t l t s(max) t s(min) 25 t p t l t s time to peak temperature (t 25oc to peak) ramp-down ramp-up preheat critical zone t l to t p
3 ? 2009 littelfuse, inc. specifcations are subject to change without notice. surface mount fuses 438 series ceramic fuse > 438 series please refer to www.littelfuse.com/series/438.html for current information. 438 series materials body: advanced ceramic terminations: ag / ni / sn (100% lead-free) element cover coating: lead-free glass moisture sensitivity level ipc/jedec j-std-020c, level 1 solderability ipc/eic/jedec j-std-002b, condition b humidity mil-std-202, method 103b, conditions d resistance to solder heat mil-std-202, method 210f, condition b product characteristics moisture resistance mil-std-202, method 106g thermal shock mil-std-202, method 107g, condition b-3 mechanical shock mil-std-202, method 213b, condition a vibration mil-std-202, method 201a vibration, high frequency mil-std-202, method 204d, condition d dissolution of metallization ipc/eic/jedec j-std-002b, condition d terminal strength iec 60127-4 dimensions 1.54 0.150 [0.061 0.006] 0.74 [0.029] 1.00 [0.039] 1.94 [0.076] 0.60 [0.024] 0.502 0.080 [0.020 0.003] 0.530 +/- 0.150 [0.021 +/- 0.006] 0.85 0.150 [0.033 0.006] 0.432 +/- 0.150 [0.017 +/- 0.006] packaging part marking system packaging option packaging specication quantity quantity packaging code 8mm tape and reel eia-481, iec 60286, part 3 3000 wr part numbering system 0438 005. w r series amp code quantity code packing code w = 3000 pcs r = reel pack .250 d .375 e .500 f .750 g 001. h 1.25 j 01.5 k 1.75 l 002. n 02.5 o 003. p 03.5 r 004. s 005. t 006. u
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