0438EWR

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 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 E10480 LR29862 AMPERE RANGE 0.250A – 6A 0.250A – 6A Features from -55ºC to +150ºC compliant and Halogenfree Applications and lead-free reflow / wave soldering Electrical Characteristics for Series % of Ampere Rating 100% 250% Ampere Rating 0.250A – 6A 0.250A – 6A Opening Time at 25ºC 4 Hours, Minimum 5 Seconds, Maximum 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 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. 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. Devices designed to be mounted with marking code facing up. Interrupting Rating Nominal Nominal Voltage Nominal Power Agency Approvals Nominal Drop At Rated Dissipation At Resistance Melting I2t (A2Sec.)3 Current (V)4 Rated Current (W) (Ohms)2 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 .250 .375 .500 .750 001. 1.25 01.5 1.75 002. 02.5 003. 03.5 004. 005. 006. 32 32 32 32 32 32 32 32 32 32 32 32 32 32 24 50 A @ 32 VDC 50 A @ 24 VDC © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/438.html for current information. 21 Revised: August 21, 2009 438 Series 438 Series S Introduction to Circuit Protection Introduction urface Mount Fuses Transientology Ceramic Fuse > 438 Series Temperature Rerating Curve Average Time Current Curves .250A .375A .500A .750A 1A 1.25A 1.5A 1.75A 2A 2.5A 3A 3.5A 4A 5A 6A 140 100 PERCENT OF RATING 120 10 100 80 TIME IN SECONDS 1 60 40 -65 -45 -25 -5 15 35 55 75 95 115 135 155 TEMPERATURE (°C) 0.1 Note: 1. Rerating depicted in this curve is in addition to the standard rerating of 20% for continuous operation. 0.01 For continuous operation at 75 degrees celsius, the fuse should be rerated as follows: I = (0.80)(0.85)IRAT = (0.68)IRAT 0.001 0.1 1 10 100 CURRENT IN AMPERES Soldering Parameters Reflow Condition - Temperature Min (Ts(min)) Pre Heat - Temperature Max (Ts(max)) - Time (Min to Max) (ts) Average Ramp-up Rate (Liquidus Temp (TL) to peak) TS(max) to TL - Ramp-up Rate Reflow - Temperature (TL) (Liquidus) - Temperature (tL) 150°C 60 – 180 seconds 3°C/second max. 5°C/second max. 217°C 60 – 150 seconds 260+0/-5 °C 10 – 30 seconds 6°C/second max. 8 minutes max. 260°C TP Ramp-up tP Critical Zone TL to TP Temperature 200°C TL TS(max) Preheat tL Ramp-down TS(min) tS 25 time to peak temperature (t 25ºC to peak) Time Peak Temperature (TP) Time within 5°C of actual peak Temperature (tp) Ramp-down Rate Time 25°C to peak Temperature (TP) Do not exceed Wave Soldering 260°C, 10 seconds max. 438 Series 22 © 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 Body: Advanced Ceramic Terminations: Ag / Ni / Sn (100% Lead-free) Element Cover Coating: Lead-free Glass Moisture Resistance Thermal Shock Mechanical Shock Vibration Vibration, High Frequency Dissolution of Metallization Terminal Strength MIL -STD-202, Method 106G MIL -STD-202, Method 107G, Materials Moisture Sensitivity Level Solderability Humidity ESD Immunity Resistance to Solder Heat Condition A MIL -STD-202, Method 201A MIL -STD-202, Method 204D, Condition D Condition D Dimensions Part Marking System Amp Code Marking Code D E F G H J K L N O P R S T U 0.530 +/- 0.150 [0.021 +/- 0.006] 1.54 ± 0.150 [0.061 ± 0.006] .250 .375 .500 .750 001. 1.25 01.5 0.85 ± 0.150 [0.033 ± 0.006] 0.502 ± 0.080 [0.020 ± 0.003] 1.75 002. 02.5 003. 03.5 004. 005. 0.432 +/- 0.150 [0.017 +/- 0.006] 006. 0.74 [0.029] 0.60 [0.024] Part Numbering System 0438 005. W R 1.00 [0.039] SERIES PACKING CODE 1.94 [0.076] AMP CODE QUANTITY CODE W = 3000 pcs Packaging Packaging Option 8mm Tape and Reel Packaging Specification Quantity 3000 Quantity & Packaging Code WR © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/438.html for current information. 23 438 Series 438 Series Introduction Introduction to Circuit Protection Transientology 24 © 2009 Littelfuse, Inc. Specifications are subject to change without notice.