0251003.MRT1L..

FUSE, PCB, 3A, 125V, VERY FAST ACTING, FULL REEL

⚠️ Reference pricing provided. In case of supply shortages, we will connect you with our trusted procurement partners to ensure your project's continuity.

Manufacturer: LITTELFUSE
Product type: PCB Fuses
Fuse Current:3A; Voltage Rating VAC:125V; Product Range:PICO II 251 Series; Voltage Rating VDC:125V; Blow Characteristic:Very Fast Acting; Fuse Case Style:Axial Leaded; D
SVHC: To Be Advised
Fuse Current: 3A
Product Range: PICO II 251 Series
Fuse Case Style: Axial Leaded
Voltage Rating VAC: 125V
Voltage Rating VDC: 125V
Blow Characteristic: Very Fast Acting
Breaking Capacity Current AC: 50A
Breaking Capacity Current DC: 300A

Delivery and price
Units per pack	4000
Price	0.461 €
Current stock	1000+
Lead time	30 days

Datasheet

**Axial Lead & Cartridge Fuses** PICO[®] ll > Very Fast-Acting Fuse > 251/253 Series 

**PS** ~~HF.Ws@ <A~~ **E** ~~**QPL**~~ 

## 251/253 Series, PICO[®] II Very Fast-Acti ~~ng Fuse~~ 

## ~~**Description** es~~ 

The PICO[®] II Very Fast-Acting Fuse is designed to meet an extensive array of performance characteristics in a space-saving subminiature package. 

## ~~**Features**~~ 

- Very fast-acting 

      - Halogen-free available 

   - Small size 

- Small size • Wide operating • Wide current rating range temperature range (0.062A- 15A) • Low temperature re-rating 

- ~~**Applications**~~ 

- ~~**Agency Approvals**~~ 

- ~~RM~~ 

Secondary protection for space constrained applications 

|**Agency**|**Agency File Number**<br>**253 Series**<br>**251 Series**<br>~~Ed~~|**Ampere Range**|
|---|---|---|
|cWAk us|E10480|0.062A - 15A|
|G.|29862|0.062A - 15A|
|**PS**<br>**E**<br>**FM10**<br>~~So~~<br>A|PSE_NBK200416-JP1021<br>J50158379<br>N/A|1A - 5A<br>0.500A - 10A<br>0.062A - 15A|
||2009010207366577|0.500A, 1A, 2A,<br>2.5A, 3A, 4A, 5A|



- Flat–panel display TV • Power supply 

- LCD monitor 

   - Audio/Video system 

- LCD backlight inverter 

   - Lighting system 

- Office machines • Medical equipment 

|~~**Electrical Characteristics for Series**~~<br>% of Ampere<br>Rating<br>Ampere Rating<br>Opening Time<br>~~TT~~|~~**Electrical Characteristics for Series**~~<br>% of Ampere<br>Rating<br>Ampere Rating<br>Opening Time<br>~~TT~~|~~**Electrical Characteristics for Series**~~<br>% of Ampere<br>Rating<br>Ampere Rating<br>Opening Time<br>~~TT~~|
|---|---|---|
|100%|0.062A - 15A|4 Hours, Min.|
||0.062A - 7A|1 Second, Max.|
|200%|10A|3 Seconds, Max.|
||12 - 15A|10 Seconds, Max.|
|275%|0.500A, 1A, 2A,<br>2.5A, 3A, 4A, 5A,<br>7A,10A|300 msecs., Max.|
|400%<br>1000%|0.5A, 1A, 2A, 2.5A,<br>3A,4A,5A,7A,10A<br>0.500A, 1A, 2A,<br>2.5A, 3A, 4A, 5A,<br>7A,10A|30 msecs., Max.<br>4 msecs., Max.|



Note:  See Electrical Specifications by Item table for specific approved ratings. 

## **Additional Information** 

**==> picture [200 x 74] intentionally omitted <==**

**----- Start of picture text -----**<br>
Datasheet Resources Samples<br>251 Series 251 Series 251 Series<br>a<br>Datasheet Resources Samples<br>253 Series 253 Series 253 Series<br>**----- End of picture text -----**<br>


© 2018 Littelfuse, Inc. Application testing is strongly recommended. Specifications are subject to change without notice. Revised: 05/31/18 

**Axial Lead & Cartridge Fuses** PICO[®] ll > Very Fast-Acting Fuse > 251/253 Series 

**==> picture [93 x 32] intentionally omitted <==**

## ~~**Electrical Specifcations by Item**~~ 

**==> picture [531 x 284] intentionally omitted <==**

**----- Start of picture text -----**<br>
Max Nominal  Nom Agency Approvals<br>Ampere  Ordering  Ordering  Nominal<br>Amp  Voltage  Interrupting Cold  Voltage<br>Rating(A) Code Number  (Std.) Number  (Mil.) Rating  Rating Resistance  I [2] Melting t (A [2 ] sec) Drop  PSE 253 Series QPL<br>(V) (Ohms)  (V) Only<br>.062 .062 251.062 253.062 125 7.000  0.000113 1.4 x x x<br>.125 .125 251.125 253.125 125 1.700  0.00174 0.285 x x x<br>.200 .200 251.200 253.200 125 0.895 0.0048 0.345 x x<br>.250 .250 251.250 253.250 125 0.665  0.0116 0.24 x x x<br>.375 .375 251.375 253.375 125 0.395  0.0296 0.215 x x x<br>.500 .500 251.500 253.500 125 0.302  0.0598 0.2165 x x x x x<br>.630 .630 251.630 125 0.205 0.08 0.188 x x<br>.750 .750 251.750 253.750 125 0.175  0.153 0.176 x x x x<br>1.00 001. 251001. 253001. 125 0.128  0.256 0.194 x x x x x x<br>1.25 1.25 2511.25 125 300 A @  0.100  0.390 0.2 x x x<br>125VDC<br>1.50 01.5 25101.5 25301.5 125 0.0823  0.587 0.21 x x x x x<br>2.00 002.  251002. 253002. 125 50A@125VAC 0.0473  0.405 0.141 x x x x x x<br>2.50 02.5 25102.5 125 0.0360  0.721 0.132 x x x x x<br>3.00 003. 251003. 253003. 125 0.0295  1.19 0.131 x x x x x x<br>3.50 03.5 25103.5 125 0.0240  1.58 0.1205 x x x x<br>4.00 004. 251004. 253004. 125 0.0204  2.45 0.114 x x x x x x<br>5.00 005. 251005. 253005. 125 0.0158  4.14 0.11 x x x x x x<br>7.00 007. 251007. 253007. 125 0.0107 10.4 0.102 x x x x<br>10.0 010. 251010. 253010. 125 0.0072 25.5 0.1 x x x x<br>12.0 012. 251012.  32 300A@32VDC0.0059 45.2 0.0878 x x<br>15.0 015. 251015. 253015.  32 & 50A@32VAC0.00446 68.8 0.071 x x x<br>**----- End of picture text -----**<br>


Note:  Higher ampere ratings are available. Please contact Littelfuse Technical Support or your Littelfuse products representative for assistance. 

© 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 05/31/18 

**Axial Lead & Cartridge Fuses** PICO[®] ll > Very Fast-Acting Fuse > 251/253 Series 

**==> picture [94 x 32] intentionally omitted <==**

**==> picture [261 x 19] intentionally omitted <==**

**----- Start of picture text -----**<br>
Temperature Re-rating Curve<br>**----- End of picture text -----**<br>


**==> picture [243 x 188] intentionally omitted <==**

Note: 

1. Re-rating depicted in this curve is in addition to the standard derating of 25% for continuous operation. 

## ~~**Soldering Parameters**~~ 

## **Recommended Process Parameters:** 

**==> picture [245 x 117] intentionally omitted <==**

**----- Start of picture text -----**<br>
Lead-Free Recommendation<br>Wave Parameter<br>for 251 Series only<br>Preheat:<br>(Depends on Flux Activation Temperature) (Typical Industry Recommendation)<br>    Temperature Minimum: 100°C<br>    Temperature Maximum: 150°C<br>    Preheat Time: 60-180 seconds<br>Solder Pot Temperature: 260°C Maximum<br>Solder Dwell Time: 2-5 seconds<br>**----- End of picture text -----**<br>


## ~~**Average Time Current Curves**~~ 

**==> picture [245 x 295] intentionally omitted <==**

**----- Start of picture text -----**<br>
100<br>10<br>1<br>0.1<br>0.01<br>0.001<br>0.05 0.1 1 10 100 1000<br>CURRENT IN AMPERES<br>.062A .125A .250A .375A .500A .630A .750A 1A 1.25A 1.5A 2A 2.5A 3A 3.5A 4A 5A 7A 10A 12A 15A<br>TIME IN SECONDS<br>**----- End of picture text -----**<br>


## **Recommended Hand Soldering Parameters:** 

Solder Iron Temperature: 350°C +/- 5°C Heating Time: 5 seconds max. 

**Note: These devices are not recommended for IR or Convection Reflow process** 

© 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 05/31/18 

**Axial Lead & Cartridge Fuses** PICO[®] ll > Very Fast-Acting Fuse > 251/253 Series 

**==> picture [93 x 32] intentionally omitted <==**

## ~~**Product Characteristics**~~ 

||Encapsulated, Epoxy-coated Body|
|---|---|
|**Materials**|251 Series: Pure tin-coated copper wire leads|
||253 Series: Solder-coated copper wire leads|
|**Solderability**|MIL-STD-202, Method 208|
|**Lead Pull Force**<br>**Fuses To MIL**<br>**SPEC**<br>**Operating**<br>**Temperature**|MIL-STD-202, Method 211, Test Condition A<br>(will withstand a 7lbs. axial pull test)<br>For fuses to MIL-PRF-23419, FM10 change the<br>series number from<br>251 to 253<br>–55ºC to +125ºC (Consider re-rating)|



|||MIL-STD-202, Method 201 (10–55||
|---|---|---|---|
||**Vibration**|Hz); Method 204, Test Condition C||
|||(55–2000 Hz at 10 G’s Peak)||
|||MIL-STD-202, Method 213, Test||
||**Shock**|Condition I (100 G’s peak for 6||
|||msecs.)||
||**Insulation Resistance**<br>**(After Opening):**|MIL-STD-202, Method 302,<br>Test Condition A (10,000 ohms<br>minimum at 100 volts)||
||**Moisture Resistance**|MIL-STD-202, Method 106||
||**Resistance to Soldering**|Withstands 60 seconds above 200OC||
||**Heat**|and up to 260ºC, maximum||
||**Flammability Rating**|UL 94V–0||
|||||
||~~**Part Numbering System**~~|||



**==> picture [262 x 19] intentionally omitted <==**

**----- Start of picture text -----**<br>
Dimensions<br>**----- End of picture text -----**<br>


**==> picture [509 x 351] intentionally omitted <==**

**----- Start of picture text -----**<br>
251 Series Markings   0251  xxxx  N R  T1 L<br>(T1 lead length)<br>27.78 52.4 (2.062")62.7 (2.468") * 27.78 Series251 = Standard type<br>(1.094" ) 7.11 (.280") (1.094" ) 253 = Military type<br>Current Rating<br>1 A L F Refer to Amp Code column of<br>2.80 Electrical Specifications Table<br>6.35 (.25") 5.0 (.197") (.11") 6.35 (.25")<br>tape MAX tape Quantity<br>1 A L F N P  = 5000= 2000<br>Wire Diameter: M  = 1000<br>0.64 (.025") for 0.062-10 amp, H  = 100<br>0.81 (.032") for 12-15 amp<br>Type of Packaging<br>R  = Reel<br>253 Series Markings  A  = Ammo Pack<br>(T3 lead length) X  = Loose Pack<br>83.31 (3.28")<br>Lead Length<br>38.1 73.0 (2.874")** 38.1 The default lead length for Ammo pack and<br>(1.5") 7.11 (.280") (1.5") Loose pack is now T1 for 251 series, and<br>remains T3 for 253 series, therefore:<br>L F 1 A T1  = 52.4mm (2.062”), 251 series only*<br>Blank  = 52.4mm (2.062”) for 251 series*<br>2.61 (.103")<br>6.35 (.25") 5.0 (.197") MAX 6.35 (.25") or 73mm (2.874”) for 253 series**<br>tape tape Option Codes<br>L F 1 A L  = RoHS + HF<br>(Only applies to 251 Series)<br>Wire Diameter:<br>0.64 (.025") for 0.062-10 amp,<br>0.81 (.032") for 15 amp Packaging<br>Packaging  Quantity &<br>Packaging Option<br>Specification  Packaging Code<br>*T1: 52.4mm (2.062")  Please refer to<br>EIA 296<br>Tape and Reel available quantities<br>above in "Part<br>**T3: 73mm (2.874')  EIA 296 Numbering<br>Tape and Reel System”<br>The default lead length for both ammo pack and loose pack is T1 for 251 and is T3 for 253.<br>**----- End of picture text -----**<br>


Notes: *   T1 dimension is defined as the length of the component between the two tapes. The full component length is 62.7mm (2.468"). **T1 length is for 251 series only.** **  T3 dimension is defined as the length of the component between the two tapes. The full component length is 83.3.7mm (3.28”). **T3 length is for 253 series only.** 

**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. 

© 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 05/31/18

Updated at June 5, 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.

About Novapart

Novapart is a B2B electronic component broker specialising in stock shortages and cost reduction. We source hard-to-find parts and identify compliant alternatives across a catalogue of 410,000+ components from 500+ manufacturers.

Learn more →

Stock Shortage Specialist

When a component is unavailable, discontinued or has an unacceptable lead time, we tap into our network of vetted European and Asian distributors to source what you need — without compromising on quality or traceability.

Request a quote →

Compliant Alternatives

We identify pin-to-pin, electrically equivalent substitutes that meet the same certifications (RoHS, AEC-Q100, REACH) as your original specification — validated against datasheets, not just part numbers. Often at a lower cost.

BOM Analysis service →