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 Approvals • Operating Temperature • Suitable for both leaded from -55ºC to +150ºC and lead-free reflow / AGENCY AGENCY FILE NUMBER AMPERE RANGE • 100% Lead-free, Halogen- wave soldering Free and RoHS compliant E10480 0.250A ~ 8A Applications 29862 0.250A ~ 8A • LCD Displays • Scanners • Servers • Data Modems Electrical Characteristics for Series • Printers % of Ampere Ampere Rating Opening Time at 25ºC Rating Additional Information 100% 250mA - 8A 4 hours, Minimum 250% 750mA - 8A 5 seconds, Maximum 350% 250mA -500mA 5 seconds, Maximum 350% 750mA - 8A 1 second, Maximum Datasheet Resources Samples Electrical Specifications by Item Agency Approvals Ampere Max. Nominal Nominal Nominal Voltage Nominal Power Amp Rating Voltage Interrupting Rating1 Resistance Melting I2t Drop At Rated Dissipation At Code (A) Rating (V) (Ohms)2 (A2Sec.)3 Current (V)4 Rated Current (W) 0.250 .250 125 2.290 0.003 0.78 0.195 x x 50 A @ 125 V AC/DC 0.375 .375 125 1.330 0.010 0.60 0.225 x x 0.500 .500 63 0.908 0.018 0.52 0.260 x x 0.750 .750 63 0.665 0.064 0.45 0.338 x x 1.00 001. 63 0.420 0.100 0.41 0.410 x x 1.25 1.25 63 50 A @ 63 V AC/DC 0.318 0.256 0.40 0.500 x x 1.50 01.5 63 0.209 0.324 0.39 0.585 x x 1.75 1.75 63 0.071 0.075 0.27 0.473 x x 2.00 002. 63 0.058 0.225 0.20 0.400 x x 2.50 02.5 32 0.043 0.441 0.15 0.375 x x 3.00 003. 32 0.033 0.506 0.14 0.420 x x 3.50 03.5 32 0.027 0.777 0.13 0.455 x x 4.00 004. 32 50 A @ 32 V AC/35 V DC 0.022 1.024 0.13 0.520 x x 5.00 005. 32 0.0159 2.30 0.13 0.650 x x 7.00 007. 32 0.0100 5.02 0.13 0.910 x x 8.00 008. 32 0.008 7.23 0.13 1.040 x x Notes: 1. AC Interrupting Rating tested at rated voltage with unity power factor. DC Interrupting Devices designed to carry rated current for 4 hours minimum. It is recommended that Rating tested at rated voltage with time constant < 0.8 msec. devices be operated continuously at no more than 80% rated current. See “Temperature 2. Nominal Resistance measured with < 10% rated current. Re-rating Curve”for additional re-rating information. 3. Contact Littelfuse if application transient surges are less than 1 ms. Devices designed to be mounted with marking code facing up. 4. Nominal Voltage Drop measured at rated current after temperature has stabilized. © 2018 Littelfuse, Inc. Specifications are subject to change without notice.Application testing is strongly recommended. Revised: 12/13/18

Surface Mount Fuses Ceramic Fuse > 437 Series Temperature Re-rating Curve Average Time Current Curves 140 10 .250A .375A.500A .750A1A1.25A 1.5A 1.75A2A2.5A3A3.5A4A5A7A8A G120 N TI A R100 F O 1 T N80 S E D C N R O PE60 EC S N 0.1 40 ME I -65 -45 -25 -5 15 35 55 75 95 115 135 155 TI 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. Example: 0.001 For continuous operation at 75 degrees celsius, the fuse should be rerated as follows: 0.1 1 10 100 I = (0.80)(0.85)IRAT = (0.68)IRAT CURRENT IN AMPERES Soldering Parameters Reflow Condition Pb – free assembly tP T P Critical Zone - Temperature Min (T ) 150°C Ramp-up TL to TP s(min) T Pre Heat -- TTeimmep e(Mraitnu rteo MMaaxx )( T(ts()max)) 2600 0–° C180 seconds eruTS(maxL) tL s ta Average Ramp-up Rate (Liquidus Temp re Ramp-down 3°C/second max. p Preheat (T) to peak) mT L S(min) T to T - Ramp-up Rate 5°C/second max. eT tS S(max) L - Temperature (T) (Liquidus) 217°C Reflow L 25 - Temperature (tL) 60 – 150 seconds time (tto 2 p5eºCak t ote pmepaekr)ature Time Peak Temperature (T ) 260+0/-5 °C P Time within 5°C of actual peak 10 – 30 seconds Temperature (t ) p Ramp-down Rate 6°C/second max. Time 25°C to peak Temperature (T ) 8 minutes max. P Do not exceed 260°C Wave Soldering 260°C, 10 seconds max. © 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 12/13/18

Surface Mount Fuses Ceramic Fuse > 437 Series Product Characteristics Body: Advanced Ceramic MIL-STD-202, Method 107, Thermal Shock Terminations: Ag / Ni / Sn (100% Lead-free) Condition B Materials Element Cover Coating: Ceramic/Lead-free MIL-STD-202, Method 213, Glass Mechanical Shock Condition A Moisture IPC/JEDEC J-STD-020, Level 1 Vibration MIL-STD-202, Method 201 Sensitivity Level Vibration, MIL-STD-202, Method 204, Solderability IPC/EIC/JEDEC J-STD-002, Condition B High Frequency Condition D Humidity Test MIL-STD-202, Method 103, Condition D Dissolution of IPC/EIC/JEDEC J-STD-002, Resistance to Metallization Condition D MIL-STD-202, Method 210, Condition B Solder Heat Terminal Strength IEC 60127-4 Moisture MIL-STD-202, Method 106 Resistance Part Marking System Dimensions Amp Code Marking Code Amp Code Marking Code 3.200 ± 0.1778 .250 D 002. NN [0.126 ± 0.007] .375 E 02.5 OO .500 F 003. PP N .750 G 03.5 RR [0.016.643 + +00.0.1004 // --00..2008] 001. H 004. SS 1.25 J 005. TT 01.5 K 007. WW 1.75 L 008. XX 3.200 ± 0.1778 [0.126 ± 0.007] 1.000 [0.039] Part Numbering System H 0437 008. W R 1.63 +0.10 / -0.2 [0.064 +0.004 / -0.008] SERIES PACKING CODE AMP CODE R = Reel Pack QUANTITY CODE 0.8179 +0.046 / -0.076 W = 3000 pcs [0.0322 +0.0018 / -0.003] Packaging 0.520 ± 0.200 [0.020 ± 0.008] Packaging Packaging Quantity & 1.000 1.500 Quantity [0.039] [0.059] Option Specification Packaging Code 8mm Tape EIA-481, IEC 3000 WR 1.800 and Reel 60286-3 [0.071] 3.500 [0.138] Disclaimer Notice - Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/disclaimer-electronics. © 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 12/13/18