Surface Mount Fuses Ceramic Fuse > 437 Series 437 Series – 1206 Fast-Acting Fuse Description This 100% Lead-free, RoHS compliant and Halogen-free fuse series has been designed specifically to provide over current protection to circuits that see high working ambient temperatures (up to 150ºC). In addition to this, the high I²t values typical of the Littelfuse Ceramic Fuse family ensure high inrush current withstand capability. Features Agency Approvals Agency Agency File Number Ampere Range E10480 0.250A ~ 8A LR29862 0.250A ~ 8A • Operating Temperature from -55ºC to +150ºC • 100% Lead-free and RoHS compliant • Suitable for both leaded and lead-free reflow / wave soldering Applications Electrical Characteristics for Series • Automotive Electronics • Printers % of Ampere Rating Ampere Rating Opening Time at 25ºC • LCD Displays • Scanners 100% 250mA - 8A 4 hours, Minimum • Servers • Data Modems 250% 750mA - 8A 5 seconds, Maximum 350% 250mA -500mA 5 seconds, Maximum 350% 750mA - 8A 1 second, Maximum Electrical Specifications by Item Ampere Max. Amp Rating Voltage Code (A) Rating (V) 250mA 375mA 500mA 750mA 1A 1.25A 1.5A 1.75A 2A 2.5A 3A 3.5A 4A 5A 7A 8A .250 .375 .500 .750 001. 1.25 01.5 1.75 002. 02.5 003. 03.5 004. 005. 007. 008. 125 125 63 63 63 63 63 63 63 32 32 32 32 32 32 32 Interrupting Rating 50 A @ 125 V AC/DC 50 A @ 63 V AC/DC 50 A @ 32 V AC/35 V DC Nominal Nominal Voltage Nominal Power Agency Approvals Nominal Dissipation At Resistance Melting I2t Drop At Rated (A2Sec.)3 Current (V)4 Rated Current (W) (Ohms)2 2.290 1.330 0.908 0.665 0.360 0.318 0.209 0.0703 0.058 0.043 0.033 0.027 0.022 0.016 0.010 0.0084 0.003 0.010 0.018 0.064 0.100 0.256 0.324 0.075 0.144 0.225 0.400 0.576 1.024 1.936 4.900 6.400 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 msecs. 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/437.html for current information. 0.78 0.60 0.52 0.45 0.41 0.40 0.39 0.27 0.17 0.14 0.15 0.16 0.16 0.09 0.11 0.067 0.195 0.225 0.260 0.335 0.415 0.496 0.579 0.474 0.345 0.363 0.462 0.560 0.618 0.484 0.760 0.539 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 x x 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. 17 Revised: June 23, 2011 437 Series 437 Series The general design ensures excellent temperature stability and performance reliability. Mount Fuses IntroductionSurface to Circuit Protection Ceramic FuseTransientology > 437 Series 7A 8A 120 10 100 80 TIME IN SECONDS PERCENT OF RATING .750A 1A 1.25 1.5A 1.75 2A 2.5A 3A 3.5A 4A 5A 100 140 .375A .500A Average Time Current Curves .250A 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: I = (0.80)(0.85)IRAT = (0.68)IRAT 0.001 1 0.1 10 100 CURRENT IN AMPERES Soldering Parameters Pb – free assembly Pre Heat - 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 437 Series tP TP Critical Zone TL to TP Ramp-up TL TS(max) Temperature Reflow Condition tL Ramp-down TS(min) 25 Preheat tS time to peak temperature (t 25ºC to peak) Time 260°C, 10 seconds max. 18 © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/437.html for current information. Surface Mount Fuses Ceramic Fuse > 437 Series Product Characteristics Materials Moisture IPC/JEDEC J-STD-020C, Level 1 Sensitivity Level Solderability IPC/EIC/JEDEC J-STD-002B, Condition B Humidity Test MIL-STD-202, Method 103B, Conditions D Resistance to Solder Heat MIL-STD-202, Method 210F, Condition B Dimensions Moisture Resistance MIL-STD-202, Method 106G Thermal Shock MIL-STD-202, Method 107G, Condition B 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 60127-4 437 Series Body: Advanced Ceramic Terminations: A g / Ni / Sn (100% Lead-free) Element Cover Coating: Lead-free Glass Part Marking System 1.000 [0.039] 1.63 +0.10 / -0.2 [0.064 +0.004 / -0.008] 3.200 ± 0.1778 [0.126 ± 0.007] Amp Code Marking Code .250 D .375 E .500 F .750 G 001. H N 0.8179 +0.046 / -0.076 [0.0332 +0.0018 / -0.003] 2 1.25 J 01.5 K 1.75 L 002. N 02.5 O 003. P 03.5 R 004. S 005. T 007. W 008. X 0.520 ± 0.200 [0.020 ± 0.08] 1.000 [0.039] Part Numbering System 1.500 [0.059] 0437 008. W R SERIES 1.800 [0.071] packing Code R = Reel Pack Amp code 3.500 [0.138] 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/437.html for current information. 19 437 Series