Surface Mount Fuses Ceramic Fuse > 438 Series 438 Series – 0603 Fast-Acting Fuse 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 150ºC. The high I²t values which is typical in the Littelfuse Ceramic Fuse family ensure high inrush current withstand capability. Features Agency Approvals AGENCY AGENCY FILE NUMBER AMPERE RANGE E10480 0.250A – 6A LR29862 0.250A – 6A • Operating Temperature from -55ºC to +150ºC • 100% Lead-free, RoHS compliant and Halogenfree • Suitable for both leaded and lead-free reflow / wave soldering Applications Electrical Characteristics for Series % of Ampere Rating Ampere Rating 100% 0.250A – 6A 4 Hours, Minimum 250% 0.250A – 6A 5 Seconds, Maximum Opening Time at 25ºC • Handheld Electronics • Hard Disk Drives • LCD Displays • SD Memory Cards • Battery Packs • Automotive Electronics Electrical Specifications by Item Ampere Max. Amp Rating Voltage Code (A) Rating (V) 0.25 0.375 0.5 0.75 1 1.25 1.5 1.75 2 2.5 3 3.5 4 5 6 .250 .375 .500 .750 001. 1.25 01.5 1.75 002. 02.5 003. 03.5 004. 005. 006. 63 63 63 63 63 63 63 63 32 32 32 32 32 32 24 Interrupting Rating 50A @ 63VDC 50A @ 32VAC 50A @ 32VDC/12VAC 50A @ 24VDC/12VAC Nominal Nominal Nominal Voltage Nominal Power Agency Approvals Resistance Melting I2t Drop At Rated Dissipation At (Ohms)2 (A2Sec.)3 Current (V)4 Rated Current (W) 2.024 1.247 0.829 0.466 0.310 0.200 0.174 0.125 0.051 0.0324 0.0252 0.0203 0.0169 0.0113 0.0087 0.0017 0.0041 0.0100 0.0281 0.0593 0.0510 0.0902 0.1440 0.1490 0.1977 0.2922 0.4752 0.6920 0.7398 1.3838 0.550 0.488 0.486 0.378 0.351 0.365 0.368 0.360 0.107 0.095 0.093 0.082 0.079 0.074 0.072 0.138 0.183 0.243 0.284 0.351 0.456 0.552 0.540 0.214 0.238 0.279 0.287 0.316 0.370 0.432 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x Notes: 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 Curve”for additional rerating information. 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. Devices designed to be mounted with marking code facing up. 3.Nominal Melting I²t measured at 1 msec. opening time. 4.Nominal Voltage Drop measured at rated current after temperature has stabilized. © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/438.html for current information. 1 Revised: February 15, 2012 438 Series 438 Series The general design ensures excellent temperature stability and performance reliability. Mount Fuses IntroductionSurface to Circuit Protection Ceramic FuseTransientology > 438 Series 120 10 100 80 TIME IN SECONDS PERCENT OF RATING .750A 1A 1.25A 1.5A 1.75A 2A 2.5A 3A 3.5A 4A 5A 6A 100 140 .250A Average Time Current Curves .375A .500A Temperature Rerating Curve 60 40 -65 -45 -25 -5 15 35 55 75 95 115 135 155 TEMPERATURE (°C) Note: 1 0.1 0.01 1.Rerating depicted in this curve is in addition to the standard rerating of 20% for continuous operation. Example: For continuous operation at 75 degrees celsius, the fuse should be rerated as follows: 0.001 0.1 I = (0.80)(0.85)IRAT = (0.68)IRAT 1 10 100 CURRENT IN AMPERES Soldering Parameters Reflow Condition - Temperature Min (Ts(min)) 150°C - Temperature Max (Ts(max)) 200°C - Time (Min to Max) (ts) 60 – 180 seconds Average Ramp-up Rate (Liquidus Temp (TL) to peak) 3°C/second max. TS(max) to TL - Ramp-up Rate 5°C/second max. Reflow - Temperature (TL) (Liquidus) 217°C - Temperature (tL) 60 – 150 seconds Peak Temperature (TP) 260+0/-5 °C Time within 5°C of actual peak Temperature (tp) 10 – 30 seconds Ramp-down Rate 6°C/second max. Time 25°C to peak Temperature (TP) 8 minutes max. Do not exceed 260°C Wave Soldering 438 Series tP TP Critical Zone TL to TP Ramp-up TL TS(max) Temperature Pre Heat Pb – free assembly tL Ramp-down TS(min) 25 Preheat tS time to peak temperature (t 25ºC to peak) Time 260°C, 10 seconds max. 2 © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/438.html for current information. Surface Mount Fuses Ceramic Fuse > 438 Series Product Characteristics MIL-STD-202, Method 106G Thermal Shock MIL-STD-202, Method 107G, Condition B-3 Moisture IPC/JEDEC J-STD-020C, Level 1 Sensitivity Level Mechanical Shock MIL-STD-202, Method 213B, Condition A Vibration MIL-STD-202, Method 201A Solderability IPC/EIC/JEDEC J-STD-002B, Condition B Humidity MIL-STD-202, Method 103B, Conditions D Vibration, High Frequency MIL-STD-202, Method 204D, Condition D Resistance to Solder Heat MIL-STD-202, Method 210F, Condition B Dissolution of Metallization IPC/EIC/JEDEC J-STD-002B, Condition D Terminal Strength IEC 60127-4 Materials Dimensions 438 Series Moisture Resistance Body: Advanced Ceramic Terminations: Ag / Ni / Sn (100% Lead-free) Element Cover Coating: Lead-free Glass Part Marking System 0.530 +/- 0.150 [0.021 +/- 0.006] Amp Code Marking Code .250 D .375 E 1.54 ± 0.150 [0.061 ± 0.006] 0.85 ± 0.150 [0.033 ± 0.006] 0.502 ± 0.080 [0.020 ± 0.003] 0.432 +/- 0.150 [0.017 +/- 0.006] 0.60 [0.024] .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 0.74 [0.029] Part Numbering System 0438 005. W R 1.00 [0.039] SERIES PACKING CODE 1.94 [0.076] R = Reel Pack AMP CODE QUANTITY CODE W = 3000 pcs Packaging Packaging Option Packaging Specification Quantity Quantity & Packaging Code 8mm Tape and Reel EIA-481, IEC 60286, Part 3 3000 WR © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/438.html for current information. 3 438 Series