21 ? 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 e 10480 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 r ating ampere r ating opening time at 25o c 100% 0.250a C 6a 4 hours, minimum 250% 0.250a C 6a 5 seconds, maximum applications ampere r ating (a) amp code max. voltage r ating (v) i nterrupting r ating nominal r esistance (ohms) 2 nominal melting i 2 t (a 2 sec.) 3 n ominal voltage drop at r ated c urrent (v) 4 nominal p ower dissipation at r ated c urrent (w) agency approvals 0.25 .250 32 50a @ 32vdc 2.024 0.0017 0.550 0.138 x x 0.375 .375 32 1.247 0.0041 0.488 0.183 x x 0.5 .500 32 0.829 0.0100 0.486 0.243 x x 0.75 .750 32 0.466 0.0281 0.378 0.284 x x 1 0 01. 32 0.310 0.0593 0.351 0.351 x x 1.25 1.25 32 0.200 0.0510 0.365 0.456 x x 1.5 01.5 32 0.174 0.0902 0.368 0.552 x x 1.75 1.75 32 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: june 23, 2011
introduction to circuit protection introduction to circuit protection transientology 22 ? 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 r efow condition pb C free assembly p re heat - temperature min (t s(min) ) 150c - temperature max (t s(max) ) 200c - time ( min to max) (t s ) 60 C 180 seconds average r amp-up r ate (l iquidus temp (t l ) to peak) 3csecond max. t s(max) to t l - r amp-up r ate 5csecond max. r efow - temperature (t l ) (liquidus) 21c - temperature (t l ) 60 C 150 seconds p eak temperature (t p ) 260 0-5 c time within 5 c of actual peak temperature (t p ) 10 C 30 seconds r amp-down r ate 6csecond max. time 25 c 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
23 ? 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 p ackaging option p ackaging specication quantity quantity p ackaging code 8mm tape and reel eia-481, iec 60286, part 3 3000 wr part numbering system 0438 005. w r series amp code qu antit y code pac king code w = 3000 pcs r = reel pack .250 d .375 e .500 f .750 g 0 01. 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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