0437TWR

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). 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. Agency Approvals AGENCY AGENCY FILE NUMBER E10480 LR29862 AMPERE RANGE 0.250A ~ 8A 0.250A ~ 8A Features from -55ºC to +150ºC RoHS compliant Applications and lead-free reflow / wave soldering Electrical Characteristics for Series % of Ampere Rating 100% 250% 350% 350% Ampere Rating 250mA - 8A 750mA - 8A 250mA -500mA 750mA - 8A Opening Time at 25ºC 4 hours, Minimum 5 seconds, Maximum 5 seconds, Maximum 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 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 2.290 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 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 50 A @ 63 V AC/DC 50 A @ 32 V AC/DC 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. 17 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. 437 Series Revised: August 3, 2009 437 Series S Introduction to Circuit Protection Introduction urface Mount Fuses Transientology Ceramic Fuse > 437 Series Temperature Rerating Curve Average Time Current Curves .375A .500A .250A .750A 1A 1.25 1.5A 1.75 2A 2.5A 3A 3.5A 4A 5A 140 100 PERCENT OF RATING 120 100 10 80 TIME IN SECONDS 60 1 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) 260+0/-5 °C 3°C/second max. 5°C/second max. 217°C 150°C TP Ramp-up 7A 8A 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 6°C/second max. 8 minutes max. 260°C Wave Soldering 260°C, 10 seconds max. 437 Series 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 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 Test ESD Immunity Resistance to Solder Heat Condition A MIL -STD-202, Method 201A MIL -STD-202, Method 204D, Condition D Condition D Dimensions 1.000 [0.039] 3.200 ± 0.1778 [0.126 ± 0.007] Part Marking System Amp Code .250 .375 .500 .750 001. 1.25 01.5 1.75 0.8179 +0.046 / -0.076 [0.0332 +0.0018 / -0.003] Marking Code D E F G H J K L N O P R S T W X 1.63 +0.10 / -0.2 [0.064 +0.004 / -0.008] N 2 002. 02.5 003. 03.5 004. 005. 007 . 008. 0.520 ± 0.200 [0.020 ± 0.08] 1.000 [0.039] 1.500 [0.059] Part Numbering System 0437 008. W R 1.800 [0.071] SERIES PACKING CODE AMP CODE QUANTITY CODE W = 3000 pcs 3.500 [0.138] Packaging Packaging Option 8mm Tape and Reel © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/437.html for current information. Packaging Specification Quantity 3000 Quantity & Packaging Code WR 437 Series 19 437 Series Introduction Introduction to Circuit Protection Transientology 20 © 2009 Littelfuse, Inc. Specifications are subject to change without notice.