0437005.WRA

SMD FUSE, FAST ACTING, 5A, 45VAC

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Manufacturer: LITTELFUSE
Product type: SMD Fuses
Fuse Current:5A; Blow Characteristic:Fast Acting; Voltage Rating VAC:45V; Voltage Rating VDC:63V; Fuse Case Style:1206 ^3216 Metric]; Product Range:437A Series; Break 34AK1034
Fuse Current: 5A
Product Range: 437A Series
Fuse Case Style: 1206 (3216 Metric)
Voltage Rating VAC: 45V
Voltage Rating VDC: 63V
Blow Characteristic: Fast Acting
Breaking Capacity Current AC: 50A
Breaking Capacity Current DC: 50A

Delivery and price
Units per pack	50
Price	1.08 €
Current stock	1000+
Lead time	30 days

Datasheet

Fuse **Datasheet** 

**437A Series** 1206 Fast-Acting Ceramic Fuse 

## OH **RoHS Pb** 

## **Description** 

The 437A Series AECQ-Compliant fuses are specifically tested to cater to secondary circuit protection needs of compact autoelectronics applications. 

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** 

- Operating Temperature from ■ Fast response to faulty -55ºC to +150ºC current to ensure over-current 

- ■ 100% Lead-free, Halogen-Free protection for sensitive and RoHS compliant electronic components 

## **Additional Information** 

- Meets Littelfuse’s automotive qualifications* 

- - Largely based on Littelfuse internal AEC-Q200 test plan. 

## **Applications** 

- Li-ion Battery ■ TFT  Display 

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- LED Lighting ■ Battery Management System 

- ■ Automotive Navigation (BMS) System ■ Clusters 

## **Electrical Characteristics for Series** 

|**% of Ampere Rating**<br>100%|**Ampere Rating**<br>0.250A − 8A|**Opening Time at 25ºC**<br>4 hours, Minimum|
|---|---|---|
|250%|0.750A − 8A|5 seconds, Maximum|
|350%|0.750A − 8A|1 second, Maximum|
||0.250A - 0.500A|5 seconds, Maximum|



## **Agency Approvals** 

|**Agency**<br>cWdus|**Agency File Number**<br>E10480|**Ampere Range**<br>0.250A − 8A|
|---|---|---|
|@.|29862|0.250A − 8A|



## **Electrical Specifications by Item** 

|**Ampere**<br>**Rating**<br>**(A)**<br>0.250|**Amp Code**<br>.250|**Max.**<br>**Voltage**<br>**Rating (V)**<br>125|**Interrupting Rating1**<br>50A @ 125VAC/DC|**Nominal**<br>**Resistance**<br>**(Ohms)2**<br>2.290|**Nominal**<br>**Melting I2t **<br>**(A2Sec.)3**<br>0.003|**Nominal Voltage**<br>**Drop At Rated**<br>**Current (V)4**<br>0.78|**Nominal Power**<br>**Dissipation At Rated**<br>**Current (W)**<br>0.195|**Agency**<br>**Approvals**|**Agency**<br>**Approvals**|
|---|---|---|---|---|---|---|---|---|---|
|||||||||x<br>Ws|x|
|0.375|.375|125||1.330|0.010|0.60|0.225|x|x|
|0.500|.500|63|50A @ 63VAC/DC|0.908|0.018|0.52|0.260|x|x|
|0.750|.750|63|50A @ 63VAC/DC<br>100A @ 63VDC|0.600|0.064|0.45|0.338|x|x|
|1.00|001.|63|50A @ 63VAC/DC|0.420|0.100|0.41|0.410|x|x|
|1.25|1.25|63||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||0.062|0.144|0.20|0.400|x|x|
|2.50|02.5|63|50A @ 45VAC/63VDC|0.043|0.441|0.15|0.375|x|x|
|3.00|003.|63||0.035|0.506|0.14|0.420|x|x|
|3.50|03.5|63||0.027|0.777|0.13|0.455|x|x|
|4.00|004.|63||0.022|1.024|0.13|0.520|x|x|
|5.00|005.|63||0.0159|2.30|0.13|0.650|x|x|
|7.00|007.|35|50A @ 32VAC/35VDC|0.0100|5.02|0.13|0.910|x|x|
|8.00|008.|35||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 Rating tested at rated voltage with time constant < 0.8 msec. 

2. Nominal Resistance measured with < 10% rated current. 

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. 

3. Nominal Melting I²t measured at 1 msec. opening time. 

4. Nominal Voltage Drop measured at rated current after temperature has stabilized. 

© 2021 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/08/21 

**6** 

Fuse **Datasheet** 

## **437A Series** 1206 Fast-Acting Ceramic Fuse a 

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Temperature Re-rating Curve<br>140<br>120<br>100<br>80<br>60<br>40<br>-65     -45      -25       -5        15       35       55       75       95      115     135    155<br>TEMPERATURE (°C)<br>PERCENT OF RATING<br>**----- End of picture text -----**<br>


## **Note:** 

1. Re-rating depicted in this curve is in addition to the standard re-rating 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 

## **Part Numbering System** 

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0437  005.  W   R   A<br>SERIES AEC-Q200 QUALIFIED<br>AMP CODE PACKING CODE<br>R = Tape and Reel<br>QUANTITY CODE<br>W = 3000 pcs<br>**----- End of picture text -----**<br>


## **Average Time Current Curves** 

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4A 5A [7A 8A]<br>100<br>10<br>1<br>0,1<br>0,01<br>0,001<br>0,1 1 10 100<br>CURRENT IN AMPERES<br>.250A .375A .500A .750A 1A 1.25A 1.5A 1.75A2A 2.5A 3A3.5A<br>TIME IN SECONDS<br>**----- End of picture text -----**<br>


## **Soldering Parameters** 

**Reflow Condition** Pb-free assembly **t** P **- Temperature Min (Ts(min))** 150°C **T** P **Critical Zone Pre Heat - Temperature Max (Ts(max))** 200°C **Ramp-up TL to TP Average Ramp-up Rate - Time (Min to Max) (ts)** 60 – 180 seconds **T** S(max) **T** L **t** L 5°C/second max. **(Liquidus Temp (TL) to peak) Ramp-down TS(max) to TL - Ramp-up Rate** 5°C/second max. **T** S(min) **Preheat Reflow - Temperature (TL) (Liquidus)** 217°C **t** S **- Temperature (tL)** 60 – 150 seconds **25 Peak Temperature (TP)** 260[+0/-5] °C **time to peak temperature Time (t 25ºC to peak) Time within 5°C of actual peak Temperature (tp)** 20 – 40 seconds **Ramp-down Rate** 5°C/second max. **Time 25°C to peak Temperature (TP)** 8 minutes max. **Do not exceed** 260°C **Wave Soldering** 260°C, 10 seconds max. 

© 2021 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/08/21 

**7** 

Fuse **Datasheet** 

**437A Series** 1206 Fast-Acting Ceramic Fuse 

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## **Product Characteristics** 

|**Materials**|**Materials**|**Materials**|**Materials**|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|**Body:**Advanced Ceramic<br>**Terminations:**Ag/Ni/Sn (100% Lead-free)<br>**Element Cover Coating:**Lead-free Glass|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|**Moisture Sensitivity**<br>**Level**||||<br>IPC/JEDEC J-STD-020, Level 1||||||||||
|**Solderability**||||IPC/EIC/JEDEC J-STD-002, Condition B||||||||||
|**Humidity Test**||||MIL-STD-202, Method 103, Conditions D||||||||||
|**Resistance to Solder**<br>**Heat**||||<br>MIL-STD-202, Method 210, Condition B||||||||||
|**Moisture**<br>**Resistance**||||MIL-STD-202, Method 106||||||||||
|**Thermal Shock**||||MIL-STD-202, Method 107,<br>Condition B||||||||||
|**Mechanical Shock**||||MIL-STD-202, Method 213,<br>Condition A||||||||||
|**Vibration**||||MIL-STD-202, Method 201||||||||||
|**Vibration,**<br>**High Frequency**||||MIL-STD-202, Method 204,<br>Condition D||||||||||
|**Dissolution of**<br>**Metallization**||||IPC/EIC/JEDEC<br>Condition D||J-STD-002,||||||||
|||||||||||||||
|**Terminal Strength**||||IEC 60127-4||||||||||
|**Dimensions**<br>3.200 ± 0.1778<br>[0.126 ± 0.007]<br>1.000<br>[0.039]<br>1.63 +0.10 / -0.2<br>[0.064 +0.004 / -0.008]<br>N<br>0.835 ± 0.15<br>[0.0329 ± 0.006]<br>2||||||**ions**||||||||
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## **Dimensions** 

|**acteristics**||
|---|---|
|**High Temperature**<br>**Storage**|MIL-STD-202 Method 108 with exemptions|
|**Thermal Shock Test**|JESD22 Method JA-104,<br>Test Conditions B and N|
|**Biased Humidity**|MIL-STD-202 Method 103, 85°C/85% RH with<br>10% operating power for 1000 hrs|
|**Operational Life**|MIL-STD-202 Method 108, Test Condition D|
|**Resistance To**<br>**Solvents**|MIL-STD-202 Method 215|
|**Mechanical Shock**|MIL-STD-202 Method 213, Test Condition C|
|**High Frequency**<br>**Vibration**|MIL-STD-202, Method 204|
|**Resistance To**<br>**Soldering Heat**|MIL-STD-202 Method 210, Test Condition B|
|**Solderability**|JESD22-B102E Method 1|
|**Terminal Strength**<br>**For SMD**|AEC Q200-006|
|**Board Flex**|AEC Q200-005|
|**Electrical**<br>**Characterization**|3 Temperature Electrical Characterization|



## **Part Marking System** 

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3.200 ± 0.1778<br>1.000 [0.126 ± 0.007] Amp Code Marking Code<br>[0.039]<br>.250 D<br>.375 E<br>1.63 +0.10 / -0.2 .500 F<br>[0.064 +0.004 / -0.008]<br>N .750 G<br>001. H<br>1.25 J<br> [0.0329 ± 0.006] 0.835 ± 0.15   01.5 K<br>1.75 L<br>2 002. N<br>[0.039]1.000 [0.059]1.500 02.5 O<br>003. P<br>1.800 3.500 R<br>[0.071]<br>004. S<br>005. T<br>[0.020 ± 0.008]0.520 ± 0.200 [0.138]3.500 007. W<br>008. |X|<br>**----- End of picture text -----**<br>


## **Packaging** 

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Packaging Option Packaging Spec i fication Quantity Quantity and Packaging Code<br>8mm Tape and Reel EIA-481, IEC 60286, Part 3 3000 WRA<br>**----- End of picture text -----**<br>


**Disclaimer Notice** - 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. 

© 2021 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/08/21 

**8**

Updated at June 7, 2026

Founded in 1927 and headquartered in Chicago, Illinois, Littelfuse is a premier global manufacturer of circuit protection, power control, and sensing technologies. Widely recognized for pioneering the first small, fast-acting protective fuse, the company has grown into an industry leader whose highly reliable components are essential to modern industrial, transportation, and consumer electronics applications worldwide. At the core of the Littelfuse portfolio is an expansive and industry-leading range of circuit protection solutions. This encompasses a massive selection of traditional fuses, fuse holders, and resettable PTC thermistor fuses designed to safely interrupt overcurrent conditions. To defend against electrical overstress, Littelfuse also provides advanced transient voltage suppression (TVS) technologies, including thousands of specialized TVS diodes, TVS varistors, and gas discharge tubes (GDTs) that ensure robust defense against voltage spikes and environmental hazards. Beyond its foundational protection components, Littelfuse manufactures a diverse array of discrete semiconductors, sensors, and switching devices. Engineers rely on their high-performance thyristors, including TRIACs and SCRs, alongside power-efficient Schottky diodes and MOSFETs for demanding power control applications. Complemented by precision proximity sensors and highly reliable reed and solid-state relays, Littelfuse delivers the critical building blocks required for secure, efficient, and complete system design.

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