Surface Mount Fuses Ceramic Fuse > 437 Series 437 Series – 1206 Fast-Acting Fuse RoHS Pb 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). The general design ensures excellent temperature stability and performance reliability. In addition to this, the high I²t values typical of the Littelfuse Ceramic Fuse family ensure high inrush current withstand capability. Features AGENCY • Suitable for both leaded and lead-free reflow / wave soldering • 100% Lead-free, HalogenFree and RoHS compliant • Operating Temperature from -55ºC to +150ºC Agency Approvals AGENCY FILE NUMBER AMPERE RANGE E10480 0.250A ~ 8A 29862 0.250A ~ 8A Electrical Characteristics for Series Applications • LCD Displays •Scanners •Servers • Data Modems •Printers % of Ampere Rating Ampere Rating Opening Time at 25ºC 100% 250mA - 8A 4 hours, Minimum 250% 750mA - 8A 5 seconds, Maximum 350% 250mA -500mA 5 seconds, Maximum 350% 750mA - 8A 1 second, Maximum Additional Information Datasheet Resources Samples 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 Rating1 50 A @ 125 V AC/DC 50 A @ 63 V AC/DC 50 A @ 32 V AC/35 V DC 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) 2.290 1.330 0.908 0.665 0.420 0.318 0.209 0.071 0.058 0.043 0.033 0.027 0.022 0.0159 0.0100 0.008 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.Contact Littelfuse if application transient surges are less than 1 ms. 4.Nominal Voltage Drop measured at rated current after temperature has stabilized. © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Application testing is strongly recommended. Revised: 04/19/16 0.003 0.010 0.018 0.064 0.100 0.1117 0.1580 0.2469 0.197 0.457 0.506 0.777 1.024 2.30 5.02 7.23 0.78 0.60 0.52 0.45 0.41 0.40 0.39 0.27 0.20 0.15 0.14 0.13 0.13 0.13 0.13 0.13 0.195 0.225 0.260 0.338 0.410 0.500 0.585 0.473 0.400 0.375 0.420 0.455 0.520 0.650 0.910 1.040 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 Re-rating Curve”for additional re-rating information. Devices designed to be mounted with marking code facing up. Surface Mount Fuses Ceramic Fuse > 437 Series 7A 8A 1.25A 1.5A 1.75A 2A 2.5A 3A 3.5A 4A 5A 120 100 1 80 60 40 -65 -45 -25 -5 15 35 55 75 95 115 135 155 TIME IN SECONDS PERCENT OF RATING 10 .750A 1A 140 .250A Average Time Current Curves .375A .500A Temperature Re-rating Curve 0.1 TEMPERATURE (°C) 0.01 Note: 1. Re-rating depicted in this curve is in addition to the standard re-rating of 20% for continuous operation. 0.001 0.1 Example: For continuous operation at 75 degrees celsius, the fuse should be rerated as follows: 1 10 100 CURRENT IN AMPERES I = (0.80)(0.85)IRAT = (0.68)IRAT 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 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. © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16 Surface Mount Fuses Ceramic Fuse > 437 Series Product Characteristics Body: Advanced Ceramic Terminations: A g / Ni / Sn (100% Lead-free) Element Cover Coating: Ceramic/Lead-free Glass Materials Moisture IPC/JEDEC J-STD-020, Level 1 Sensitivity Level Solderability IPC/EIC/JEDEC J-STD-002, Condition B Humidity Test MIL-STD-202, Method 103, Condition D Resistance to Solder Heat Moisture Resistance MIL-STD-202, Method 210, Condition B MIL-STD-202, Method 107, Condition B MIL-STD-202, Method 213, Condition A Thermal Shock Mechanical Shock Vibration MIL-STD-202, Method 201 Vibration, High Frequency Dissolution of Metallization MIL-STD-202, Method 204, Condition D Terminal Strength IEC 60127-4 IPC/EIC/JEDEC J-STD-002, Condition D MIL-STD-202, Method 106 Dimensions Part Marking System 3.200 ± 0.1778 [0.126 ± 0.007] 1.63 +0.10 / -0.2 [0.064 +0.004 / -0.008] 1.000 [0.039] 1.63 +0.10 / -0.2 [0.064 +0.004 / -0.008] N 3.200 ± 0.1778 [0.126 ± 0.007] H Amp Code Marking Code .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 007. W 008. X 0.8179 +0.046 / -0.076 [0.0322 +0.0018 / -0.003] Part Numbering System 0.520 ± 0.200 [0.020 ± 0.008] 0437 008. W R 1.000 [0.039] 1.500 [0.059] SERIES PACKING CODE 1.800 [0.071] R = Reel Pack AMP CODE QUANTITY CODE 3.500 [0.138] W = 3000 pcs Packaging Packaging Option Packaging Specification Quantity Quantity & Packaging Code 8mm Tape and Reel EIA-481, IEC 60286-3 3000 WR © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16