RF3361-000

PPTC RESETTABLE FUSE, RECT, 40A, 60VDC

⚠️ 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: Radial Leaded PPTCs
Product Range:PolySwitch RKEF Series; Voltage Rating:60VDC; Holding Current:500mA; Trip Current:1A; Time to Trip:0.8s; Fuse Shape:Rectangular; Current Rating Ma 27AM6633
SVHC: To Be Advised
Height: 0.45"
Length: 0.28"
Diameter: -
Thickness: 0.14"
Fuse Shape: Rectangular
Lead Spacing: 0.23"
Time to Trip: 0.8s
Trip Current: 1A
Product Range: PolySwitch RKEF Series
Voltage Rating: 60VDC
Holding Current: 500mA
Current Rating Max: 40A
Operating Temperature Max: 85°C
Operating Temperature Min: -40°C
Automotive Qualification Standard: -

Delivery and price
Units per pack	500
Price	0.336 €
Current stock	1000+
Lead time	30 days

Datasheet

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

## RoHS HFL 1® 

## **Description** 

Littelfuse PolySwitch radial-leaded devices represent the most comprehensive and complete set of PPTC products available in the industry today. RKEF series is for balance of voltage rating (60V) and hold current (up to 5A). 

## **Features & Benefits** 

- Resettable and single-use overcurrent devices 

- Wide range of form factor and termination methods 

- Devices compatible with high-volume electronics assembly 

- RoHS compliant, Lead-Free and Halogen-Free 

## **Applications** 

## **Additional Information** 

- Satellite video receivers ■ CD-ROMs 

- Industrial controls ■ Game machines 

- Transformers ■ Battery packs 

- Computer motherboards ■ Phones 

- Modems ■ Fax machines 

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Resources Accessories Samples<br>**----- End of picture text -----**<br>


- USB hubs, ports and ■ Analog and digital line cards peripherals ■ Printers 

- IEEE 1394 ports 

## **Agency Approvals** 

|**Agency**|**Agency File Number**|
|---|---|
|Aw|E74889|
|6.|78165|
|~~A~~|72161791|



## **Electrical Characteristics** 

|RKEF050|RF3054-000|0.50|1.00|60|—|40|—|1.00|8.00|0.8|0.320|0.529|0.900|0.205/24|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|RKEF065|RF3363-000|0.65|1.30|60|—|40|—|1.25|8.00|1.0|0.250|0.450|0.720|0.205/24|
|RKEF075|RF3365-000|0.75|1.50|60|—|40|—|1.40|8.00|1.5|0.200|0.390|0.640|0.205/24|
|RKEF090|RF3366-000|0.90|1.80|60|—|40|—|1.50|8.00|2.0|0.190|0.320|0.520|0.205/24|
|RKEF110|RF3367-000|1.10|2.20|60|—|40|—|2.20|8.00|3.0|0.170|0.280|0.470|0.520/20|
|RKEF135|RF3369-000|1.35|2.70|60|—|40|—|2.30|8.00|4.5|0.110|0.220|0.370|0.520/20|
|RKEF160|RF3370-000|1.60|3.20|60|—|40|—|2.40|8.20|9.0|0.100|0.200|0.320|0.520/20|
|RKEF185|RF3371-000|1.85|3.70|60|—|40|—|2.60|9.25|12.6|0.060|0.152|0.250|0.520/20|
|RKEF250|RF3372-000|2.50|5.00|60|—|40|—|2.80|12.50|15.6|0.040|0.085|0.140|0.520/20|
|RKEF300|RF3374-000|3.00|6.00|60|—|40|—|3.20|15.00|19.8|0.030|0.050|0.080|0.520/20|
|RKEF375|RF3375-000|3.75|7.50|60|—|40|—|3.40|18.75|22.0|0.017|0.040|0.060|0.520/20|
|RKEF400|RF3377-000|4.00|8.00|60|—|40|—|3.70|20.00|24.0|0.014|0.038|0.060|0.520/20|
|RKEF500|RF3058-000|5.00|10.00|60|—|40|—|5.00|25.00|28.0|0.012|0.030|0.050|0.520/20|



## **Notes:** 

IH : Hold current: maximum current device will pass without interruption in 20°C still air. 

IT : Trip current: minimum current that will switch the device from low resistance to high resistance in 20°C still air. 

- VMAX : Maximum continuous voltage device can withstand without damage at rated current. 

- IMAX : Maximum fault current device can withstand without damage at rated voltage. 

- PD : Power dissipated from device when in the tripped state in 20°C still air. 

RMIN : Minimum resistance of device as supplied at 20°C unless otherwise specified. 

- RMAX : Maximum resistance of device as supplied at 20°C unless otherwise specified. 

- R1MAX : Maximum resistance of device when measured one hour post reflow (surface-mount device) or one hour post trip  (radial-leaded device) at 20°C unless otherwise specified. 

- Electrical characteristics determined at 25°C. 

© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**1** 

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

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## **Temperature Rerating** 

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Maximum Ambient Temperature<br>-40°C  -20°C  0°C  20°C   25°C  40°C 50°C 60°C 70°C 85°C<br>Hold Current (A)<br>RKEF – 60V<br>RKEF050 0.73 0.65 0.58 0.50 0.48 0.42 0.38 0.34 0.31 0.26<br>RKEF065 0.94 0.85 0.75 0.65 0.63 0.54 0.50 0.44 0.40 0.34<br>RKEF075 1.09 0.98 0.86 0.75 0.73 0.62 0.58 0.51 0.46 0.39<br>RKEF090 1.30 1.17 1.04 0.90 0.87 0.75 0.69 0.61 0.55 0.47<br>RKEF110 1.60 1.43 1.27 1.10 1.06 0.92 0.85 0.75 0.67 0.57<br>RKEF135 1.96 1.76 1.55 1.35 1.31 1.12 1.04 0.92 0.83 0.71<br>RKEF160 2.32 2.08 1.84 1.60 1.55 1.33 1.23 1.08 0.98 0.83<br>RKEF185 2.68 2.41 2.13 1.85 1.79 1.54 1.43 1.26 1.13 0.96<br>RKEF250 3.63 3.25 2.88 2.50 2.43 2.08 1.93 1.70 1.52 1.31<br>RKEF300 4.35 3.90 3.45 3.00 2.91 2.50 2.30 2.04 1.84 1.55<br>RKEF375 5.44 4.88 4.31 3.75 3.64 3.11 2.90 2.54 2.29 1.94<br>RKEF400 5.80 5.20 4.60 4.00 3.88 3.32 3.08 2.73 2.45 2.08<br>RKEF500 7.25 6.50 5.75 5.00 4.85 4.15 3.85 3.41 3.06 2.59<br>**----- End of picture text -----**<br>


## **Temperature Rerating Curve** 

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200<br>150<br>100<br>50<br>0<br>-40 -20 0 20 40 60 80<br>Ambient Temperature (˚C)<br>% of Rated Hold and Trip Current<br>**----- End of picture text -----**<br>


© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**2** 

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

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## **Typical Time-to-Trip Curves at 20°C** 

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RKEF A =  RKEF050 H =  RKEF185 100 E F G H I J K L M<br>B =  RKEF065 I  =  RKEF250 A B C D<br>C =  RKEF075 J =  RKEF300 10<br>D =  RKEF090 K =  RKEF375<br>E =  RKEF110 L =  RKEF400 M<br>F =  RKEF135 M =  RKEF500<br>1 L<br>G =  RKEF160 K<br>J<br>I<br>0.1<br>H<br>G<br>F<br>0.011 10 A BCD E 100<br>Fault Current (A)<br>Time-to-Trip (s)<br>**----- End of picture text -----**<br>


## **Physical Specifications** 

|**Lead Material**|RKEF050 to 090 : Tin-plated Copper, 0.205mm2(24AWG), ø0.51mm (0.020in)<br>RKEF110 to 500 : Tin-plated Copper, 0.52mm2(20AWG), ø0.81mm (0.032in)|
|---|---|
|**Soldering Characteristics**|Solderability per ANSI/J-STD-002 Category 3|
|**Solder Heat Withstand**|RKEF050-RKEF185: per IEC-STD 60068-2-20, Test Tb, Method 1;<br>Can withstand 5s at 260°C ±5°C<br>All Other Sizes: per IEC-STD 60068-2-20, Test Tb, Method 1;<br>Can withstand 10s at 260°C ±5°C|
|**Insulating Material**|Cured, Flame-retardant Epoxy Polymer; Meets UL 94V-0|
|**Operation Temperature**|-40°C~85°C|



**Note:** Devices are not designed to be placed through a reflow process. 

## **Environmental Specifications** 

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Test Conditions Resistance Change<br>-40°C, 1000 hrs ±5%<br>Passive Aging<br>85°C, 1000 hrs ±5%<br>Humidity Aging 85°C, 85% R.H., 1000 hrs ±10%<br>Thermal Shock 85°C, -40°C (10 Times) ±10%<br>Solvent Resistance MIL-STD-202, Method 215F No change<br>Moisture Resistance Level Level 1, J-STD-020<br>40°C max, 70% RH max; devices should remain in original sealed bags prior to use.<br>Storage Conditions  Devices may not meet specified values if these storage conditions are exceeded.<br>**----- End of picture text -----**<br>


© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**3** 

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

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**Dimension Figures** 

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A E A E<br>B B A<br>C<br>J<br>J E H<br>D<br>D<br>Figure 3 Figure 4<br>C F C F<br>CL to CL CL CL CL to CL CL CL<br>**----- End of picture text -----**<br>


**Figure 1** 

**Figure 2** 

**Dimensions and Weights** 

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Dimensions in Millimeters (Inches)<br>Part Number A B C D E Figure Device Mass (g)<br>(Only for Reference)<br>Min Max Min Max Min Max Min Max Min Max<br>RKEF – 60V<br>7.10  11.43  4.32  5.84  7.60  3.56<br>RKEF050 —  —  —  —  1,3,4 0.166<br>(0.28) (0.45) (0.17) (0.23) (0.30) (0.14)<br>7.11  12.20  4.32  5.84  7.60  3.56<br>RKEF065 — —  —  —  1,3,4 0.182<br>( 0 .28) (0.48) (0.17) (0.23) (0.30) (0.14)<br>7.87  12.20  4.32  5.84  7.60  3.56<br>RKEF075 —  —  —  —  1,3,4 0.201<br>(0.31) (0.48) (0.17) (0.23) (0.30) (0.14)<br>7.87  13.97  4.32  5.84  7.60  3.56<br>RKEF090 —  —  —  —  1,3,4 0.235<br>(0.31) (0.55) (0.17) (0.23) (0.30) (0.14)<br>7.60  15.00  4.32  5.84  7.60  4.10<br>RKEF110 —  —  —  —  1,3,4 0.353<br>(0.30) (0.59) (0.17) (0.23) (0.30) (0.16)<br>10.20  17.00  4.32  5.84  7.60  3.81<br>RKEF135 —  —  —  —  2,3,4 0.438<br>(0.40) (0.67) (0.17) (0.23) (0.30) (0.15)<br>12.20  18.30  4.32  5.84  7.60  3.81<br>RKEF160 —  —  —  —  2,3,4 0.546<br>(0.48) (0.72) (0.17) (0.23) (0.30) (0.15)<br>13.00  18.80  4.32  5.84  7.60  3.81<br>RKEF185 —  —  —  —  2,3,4 0.538<br>(0.51) (0.74) (0.17) (0.23) (0.30) (0.15)<br>14.00  20.60  4.32  5.84  7.60  3.00<br>RKEF250 —  —  —  —  2,3,4 0.775<br>(0.55) (0.81) (0.17) (0.23) (0.30) (0.12)<br>16.50  21.20  4.32  5.84  7.60  3.00<br>RKEF300 —  —  —  —  2,3,4 0.971<br>(0.65) (0.83) (0.17) (0.23) (0.30) (0.12)<br>16.50  25.20  9.40  10.90  7.60  3.00<br>RKEF375 —  —  —  —  2,3,4 1.142<br>(0.65) (0.99) (0.37) (0.43) (0.30) (0.12)<br>21.00  24.90  9.40  10.90  7.60  3.00<br>RKEF400 —  —  —  —  2,3,4 1.391<br>(0.83) (0.98) (0.37) (0.43) (0.30) (0.12)<br>24.10  29.00  9.40  10.90  7.60  3.00<br>RKEF500 — — —  — 2,3,4 1.783<br>(0.95) (1.14) (0.37) (0.43) (0.30) (0.12)<br>**----- End of picture text -----**<br>


© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**4** 

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

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## **Packaging and Marking Information** 

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Part Bag Tape and Reel   Ammo Pack   Standard Package  Part   Agency<br>Number Quantity Quantity Quantity Quantity Marking Recognition<br>RKEF – 60V<br>RKEF050 500 — — 10,000 K50 UL, CSA, TÜV<br>RKEF065 500 — — 10,000 K65 UL, CSA, TÜV<br>RKEF075 500 — — 10,000 K75 UL, CSA, TÜV<br>RKEF090 500 — — 10,000 K90 UL, CSA, TÜV<br>RKEF110 500 — — 10,000 K110 UL, CSA, TÜV<br>RKEF135 500 — — 10,000 K135 UL, CSA, TÜV<br>RKEF160 500 — — 10,000 K160 UL, CSA, TÜV<br>RKEF185 500 — — 10,000 K185 UL, CSA, TÜV<br>RKEF250 500 — — 10,000 K250 UL, CSA, TÜV<br>RKEF300 250 — — 5,000 K300 UL, CSA, TÜV<br>RKEF375 250 — — 5,000 K375 UL, CSA, TÜV<br>RKEF400 250 — — 5,000 K400 UL, CSA, TÜV<br>RKEF500 250 — — 5,000 K500 UL, CSA, TÜV<br>**----- End of picture text -----**<br>


## **Part Ordering Number System** 

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RKEF   250   U   2<br>**----- End of picture text -----**<br>


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Packaging<br>Blank = Packaged in Bags<br>-1   = 25.4mm (1.0 in) Minimum Lead Length<br>-2   = Tape and Reel<br>-AP  = Ammo Pack<br>-X.X = Special Lead Cut Length (in)<br>Modifier<br>K   = Standard Kinked Lead<br>B   = Special Kinked Lead<br>S   = Straight Lead<br>U   = Uncoated Device<br>Hold Current Indicator<br>Product Series<br>An “F” at the end of product series indicates Pb-free version of product.<br>**----- End of picture text -----**<br>


**Note:** Kinked parts are recommended to control the height of the part on the PCB in non-auto PCB applications. 

© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**5** 

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

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## **Tape and Reel Specifications** 

RKEF devices are available in tape and reel packaging per EIA468-B/IEC60286-2 standards. See Figures 1 and 2 for details. 

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Description EIA Mark Dimension (mm) Tolerance<br>Carrier Tape Width W 18 -0.5/+1.0<br>Hold-Down Tape Width W4 11 Minimum<br>Top Distance between Tape Edges W6 3 Maximum<br>Sprocket Hole Position W5 9 -0.5/+0.75<br>Sprocket Hole Diameter D0 4 ± 0.2<br>Abscissa to Plane (Straight Lead) (RKEF135 To RKEF500) H 18.5 ± 2.5<br>Abscissa to Plane (Kinked Lead) (RKEF050 To RKEF110) H0 16.0 ± 0.5<br>Abscissa to Top (RKEF050 To RKEF185) H1 32.2 Maximum<br>Abscissa to Top* (RKEF250 To RKEF500) H1 47.5 Maximum<br>Overall Width with Lead Protrusion (RKEF050 To RKEF185) C1 43.2 Maximum<br>Overall Width with Lead Protrusion* (RKEF250 To RKEF500) C1 58 Maximum<br>Overall Width without Lead Protrusion (RKEF050 To RKEF185) C2 42.5 Maximum<br>Overall Width without Lead Protrusion* (RKEF250 To RKEF500) C2 57.0 Maximum<br>Lead Protrusion L1 1.0 Maximum<br>Protrusion of Cut-Out L 11.0 Maximum<br>Protrusion beyond Hold-down Tape I2 Not Specified —<br>Sprocket Hole Pitch P0 12.7 ± 0.3<br>Device Pitch (RKEF050 To RKEF185) — 12.7 ± 0.3<br>Device Pitch (RKEF250 To RKEF500) — 25.4 ± 0.61<br>Pitch Tolerance — 20 Consecutive ± 1<br>Tape Thickness T 0.9 Maximum<br>Overall Tape and Lead Thickness (RKEF050 To RKEF185) T1 1.5 Maximum<br>Overall Tape and Lead Thickness (RKEF250 To RKEF500) T1 2.3 Maximum<br>Splice Sprocket Hole Alignment — 0 ± 0.3<br>Body Lateral Deviation h 0 ± 1.0<br>Body Tape Plane Deviation p 0 ± 1.3<br>Ordinate to Adjacent Component Lead  (RKEF050 To RKEF300) P1 3.81 ± 0.7<br>Ordinate to Adjacent Component Lead  (RKEF375 To RKEF500)  P1 7.62 ± 0.7<br>Lead Spacing*  (RKEF050 To RKEF300) F 5.05 ± 0.75<br>Lead Spacing*  (RKEF375 To RKEF500) F 10.15 ± 0.75<br>Reel Width  (RKEF050 To RKEF185) W2 56.0 Maximum<br>Reel Width*  (RKEF250 To RKEF500) W2 63.5 Maximum<br>Reel Diameter A 370.0 Maximum<br>Space between Flanges*  (RKEF050 To RKEF185) W1 48.0 Maximum<br>Space between Flanges*  (RKEF250 To RKEF500) W1 55.0 Maximum<br>Arbor Hold Diameter C 26.0 ± 12.0<br>Core Diameter* N 91.0 Maximum<br>Box — 64/372/362 Maximum<br>Consecutive Missing Places — None —<br>Empty Places per Reel — 0.1% Maximum<br>**----- End of picture text -----**<br>


*Differs from EIA specification. 

© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**6** 

PTC **Datasheet** 

**RKEF Series** Radial Leaded 

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## **Tape and Reel Diagrams** 

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�h �h �p �p<br>Reference Plane<br>H1 P1 H1 C2<br>F H C1<br>L A B D4 H0 W5<br>W<br>I2<br>L1 P0 D0 Direction of Unreeling<br>Figure 1 Cross Section A-B<br>t<br>Reel<br>Upper Side<br>n<br>Type<br>a Direction of<br>Unreeling<br>Lower Side<br>c<br>w 1<br>Cross Section<br>w 2<br>Optional Shape: Circular or Polygonal<br>Figure 2<br>**----- End of picture text -----**<br>


## **Warning** 

- Users should independently evaluate the suitability of and test each product selected for their own application. 

- Operation beyond the maximum ratings or improper use may result in device damage and possible electrical arcing and flame. 

- These devices are intended for protection against damage caused by occasional overcurrent or overtemperature fault conditions and should not be used when repeated fault conditions or prolonged trip events are anticipated. 

- Contamination of the PPTC material with certain silicone-based oils or some aggressive solvents can adversely impact the performance of the devices. 

- Device performance can be impacted negatively if devices are handled in a manner inconsistent with recommended electronic, thermal, and mechanical procedures for electronic components. 

- PPTC devices are not recommended for installation in applications where the device is constrained such that its PTC properties are inhibited, for example in rigid potting materials or in rigid housings, which lack adequate clearance to accommodate device expansion. 

- Operation in circuits with a large inductance can generate a circuit voltage (Ldi/dt) above the rated voltage of the device. 

**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. 

© 2022 Littelfuse, Inc. Specifications are subject to change without notice. Revised: GD. 09/12/22 

**7**

Updated at June 9, 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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