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RF4298-000
Resettable Fuse, PPTC, 2920 (7351 Metric), PolySwitch SMDC Series, 33 VDC, 1.25 A, 2.5 A, 2 s
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- Manufacturer: LITTELFUSE
- Product type: Surface Mount PPTCs
- SVHC: To Be Advised
- Time to Trip: 2s
- Trip Current: 2.5A
- Product Range: PolySwitch SMDC Series
- Voltage Rating: 33VDC
- Holding Current: 1.25A
- PPTC Case Style: 2920 (7351 Metric)
- Current Rating Max: 40A
- Operating Temperature Max: 85°C
- Operating Temperature Min: -40°C
- Automotive Qualification Standard: -
| Delivery and price | |
|---|---|
| Units per pack | 2000 |
| Price | 0.275 € |
| Current stock | 1000+ |
| Lead time | 30 days |
Datasheet
**PolySwitch[®] Resettable PPTCs** Surface Mount > SMDC Series ## SMDC Series ## **R** ~~**oHS**~~ ## **Description** The SMDC series provides surface mount overcurrent protection for applications where space is at a premium and resettable protection is desired. ## **Features** - Broadest range of resettable devices available in industry - Low resistance - Small 2920 footprint - Fast time-to-trip - RoHS complaint, lead-free and halogen-free **Agency Approvals** Ee, **Agency Agency File Number** E74889 @. 78165 A 72161779 ~~—~~ ## **Applications** - Mobile Electronics and Batteries - Computer - Portable electronics - Multimedia - Game machines - Telephone and broadband - Automotive - Industrial controls - Battery ## **Additional Information** **==> picture [192 x 7] intentionally omitted <==** **----- Start of picture text -----**<br> Datasheet Resources Samples<br>**----- End of picture text -----**<br> ## **Electrical Characteristics** ~~[~~ |**Part**<br>**Number**<br>SMDC030F<br>SMDC050F<br>SMDC075F<br>SMDC125F/33<br>SMDC185F/33<br>SMDC300F/24<br>~~Po ~~<br>~~SS ~~<br>~~ee ~~<br>~~ee ~~|**Part**<br>**Number**<br>SMDC030F<br>SMDC050F<br>SMDC075F<br>SMDC125F/33<br>SMDC185F/33<br>SMDC300F/24<br>~~Po ~~<br>~~SS ~~<br>~~ee ~~<br>~~ee ~~|**IH**<br>**IT**<br>**VMAX**<br>**IMAX**<br>**PD MAX**<br>**(A)**<br>**(A)**<br>**(VDC)**<br>**(A)**<br>**(W)**<br>**SMDC Series — Size 7555mm/2920mils**<br>0.30<br>0.60<br>60<br>10<br>1.50<br>0.50<br>1.00<br>60<br>10<br>1.50<br>0.75<br>1.5<br>33<br>40<br>1.50<br>1.25<br>2.50<br>33<br>40<br>1.50<br>1.85<br>3.70<br>33<br>40<br>1.70<br>3.00<br>6.00<br>24<br>40<br>1.70<br> ~~Ff~~<br> ~~SE~~<br> ~~ee nee~~<br> ~~ee nee~~|**Max Time-to-trip**<br>**(A)**<br>**(s)**<br>1.50<br>3.00<br>2.50<br>4.00<br>8.00<br>0.30<br>8.00<br>2.00<br>8.00<br>2.50<br>8.00<br>5.00|**Max Time-to-trip**<br>**(A)**<br>**(s)**<br>1.50<br>3.00<br>2.50<br>4.00<br>8.00<br>0.30<br>8.00<br>2.00<br>8.00<br>2.50<br>8.00<br>5.00|**RMIN**<br>**R1MAX**<br>**(Ω)**<br>**(Ω)**<br>0.300<br>3.400<br>0.150<br>1.200<br>0.100<br>0.610<br>0.040<br>0.250<br>0.050<br>0.150<br>0.015<br>0.072<br>~~ee~~<br>~~ee~~| |---|---|---|---|---|---| ||SMDC310F/18|3.10<br>6.00<br>18<br>50<br>1.50|8.00|25.00|0.013<br>0.036| ## **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. - **R1MAX** : Maximum resistance measured one hour post-trip or post-reflow at 20°C. © 2020 Littelfuse, Inc. Specifications are subject to change without notice. Revised: BA.09/30/20 **PolySwitch[®] Resettable PPTCs** Surface Mount > SMDC Series **==> picture [93 x 32] intentionally omitted <==** ## **Temperature Rerating** **==> picture [506 x 134] intentionally omitted <==** **----- Start of picture text -----**<br> Maximum Ambient Temperature<br>Part Number -40°C -20°C 0°C 20°C 25°C 40°C 50°C 60°C 70°C 80°C 85°C<br>Hold Current (A)<br>SMDC Series — Size 7555mm/2920mils<br>SMDC030F 0.490 0.430 0.370 0.310 0.300 0.250 0.220 0.190 0.160 0.141 0.120<br>SMDC050F 0.860 0.750 0.650 0.540 0.500 0.430 0.370 0.320 0.260 0.224 0.180<br>SMDC075F 1.170 1.040 0.900 0.770 0.750 0.640 0.570 0.500 0.440 0.323 0.340<br>SMDC125F/33 2.02 1.78 1.55 1.31 1.25 1.08 0.96 0.84 0.72 0.60 0.54<br>SMDC185F/33 2.83 2.50 2.20 1.85 1.74 1.53 1.37 1.22 1.04 0.88 0.80<br>SMDC300F/24 4.70 4.19 3.70 3.17 3.00 2.66 2.41 2.20 1.90 1.65 1.50<br>SMDC310F/18 4.50 4.06 3.78 3.19 3.10 2.75 2.54 2.32 2.10 1.88 1.76<br>**----- End of picture text -----**<br> **==> picture [243 x 19] intentionally omitted <==** **----- Start of picture text -----**<br> Temperature Rerating Curve<br>**----- End of picture text -----**<br> **==> picture [243 x 22] intentionally omitted <==** **----- Start of picture text -----**<br> Typical Time-to-Trip Curves at 20°C<br>**----- End of picture text -----**<br> **==> picture [504 x 183] intentionally omitted <==** **----- Start of picture text -----**<br> 200 100<br>180 G<br>160 10 A B C D E F<br>140<br>120<br>1<br>100<br>80<br>0.1<br>60 G<br>40 F<br>0.01 B<br>20 A C E<br>0 D<br>-40 -20 0 20 40 60 80 100 120 0.001<br>Ambient Temperature (°C) 0.1 1 10 100<br>A = SMDC030F E = SMDC185F/33<br>B = SMDC050F F = SMDC300F/24<br>C = SMDC075F G = SMDC310F/18<br>D = SMDC125F/33<br>Time-to-Trip (s)<br>% of Rated Hold and Trip Current<br>**----- End of picture text -----**<br> ## **Physical Specifications** **Terminal Pad Material** 100% Matte Tin with Nickel Underplate **Soldering Characteristics** ANSI/J-STD-002 Category 3 **Solder Heat Withstand** per IEC-STD 68-2-20, Test Tb, Section 5, Method 1a per IEC 695-2-2 Needle Flame Test for 20 **Flammability Resistance** seconds ## **Environmental Specifications** **==> picture [506 x 110] intentionally omitted <==** **----- Start of picture text -----**<br> Test Test Method Conditions Resistance Change<br>Storage Life PS300, Section 5.3.2 60°C, 1000 hrs, 85°C, 1000 hrs ±3% typ, ±5% typ<br>Humidity Aging PS300, Section 5.3.1 85°C, 85% R.H., 100 hrs ±1.2% typ<br>Thermal Shock MIL-STD-202, Method 107G 85°C, -40°C (20 Times) -33% typ<br>Vibration MIL-STD-883C per MIL-STD-883C No Change<br>Solvent Resistance PS300, Section 5.2.2 Freon, Trichloroethane, Hydrocarbons No Change<br>Moisture Resistance Level Level 2a, 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> © 2020 Littelfuse, Inc. Specifications are subject to change without notice. Revised: BA.09/30/20 **PolySwitch[®] Resettable PPTCs** Surface Mount > SMDC Series **==> picture [93 x 32] intentionally omitted <==** ## **Dimension Figures** **==> picture [105 x 77] intentionally omitted <==** **----- Start of picture text -----**<br> A B<br>C<br>D E<br>Figure 1<br>**----- End of picture text -----**<br> ## **Dimensions** **==> picture [506 x 165] intentionally omitted <==** **----- Start of picture text -----**<br> Dimensions in Millimeters (Inches)<br>Part Number A B C D E Figure<br>Min Max Min Max Min Max Min Max Min Max<br>SMDC Series — Size 7555mm/2920mils<br>SMDC030F 7.30 7.70 0.63 0.90 4.90 5.30 0.25 0.95 0.20 - 1<br>(0.287) (0.303) (0.025) (0.035) (0.193) (0.209) (0.010) (0.040) (0.008)<br>SMDC050F 7.30 7.70 0.63 0.90 4.90 5.30 0.25 0.95 0.20 - 1<br>(0.287) (0.303) (0.025) (0.035) (0.193) (0.209) (0.010) (0.040) (0.008)<br>SMDC075F 7.30 7.70 0.63 0.90 4.90 5.30 0.25 0.95 0.20 - 1<br>(0.287) (0.303) (0.025) (0.035) (0.193) (0.209) (0.010) (0.040) (0.008)<br>SMDC125F/33 7.30 7.70 0.45 0.71 4.90 5.30 0.25 0.95 0.20 — 1<br>(0.287) (0.303) (0.018) (0.028) (0.193) (0.209) (0.010) (0.040) (0.008)<br>SMDC185F/33 7.30 7.70 0.90 1.20 4.90 5.30 0.25 0.95 0.20 — 1<br>(0.287) (0.303) (0.035) (0.047) (0.193) (0.209) (0.010) (0.040) (0.008)<br>SMDC300F/24 7.30 7.70 0.80 1.10 4.90 5.30 0.25 0.95 0.20 — 1<br>(0.287) (0.303) (0.031) (0.043) (0.193) (0.209) (0.010) (0.040) (0.008)<br>SMDC310F/18 7.30 7.70 1.10 1.70 4.90 5.30 0.95 1.45 0.35 — 1<br>(0.287) (0.303) (0.043) (0.067) (0.193) (0.209) (0.037) (0.057) (0.014)<br>**----- End of picture text -----**<br> ## **Recommended Pad Layout** **==> picture [125 x 68] intentionally omitted <==** **----- Start of picture text -----**<br> A<br>B C B<br>Figure 2<br>**----- End of picture text -----**<br> ## **Recommended Pad Layout** **==> picture [506 x 108] intentionally omitted <==** **----- Start of picture text -----**<br> Recommended Pad Layout Figures<br>Part Tape and Reel Standard Part [mm (in)] Agency<br>Number Quantity Package Marking Dimension A Dimension B Dimension C Recognition<br>(Nom) (Nom) (Nom)<br>SMDC Series — Size 7555mm/2920mils<br>SMDC030F 4,000 20,000 030F 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) -<br>SMDC050F 4,000 20,000 050F 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) -<br>SMDC075F 4,000 20,000 075F 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) -<br>SMDC125F/33 4,000 20,000 125F 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL<br>SMDC185F/33 4,000 20,000 185F 33V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TÜV<br>SMDC300F/24 4,000 20,000 300F 24V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TÜV<br>SMDC310F/18 3,000 15,000 310F 18V 5.30 (0.209) 2.00 (0.079) 4.60 (0.18) UL, CSA, TUV<br>**----- End of picture text -----**<br> © 2020 Littelfuse, Inc. Specifications are subject to change without notice. Revised: BA.09/30/20 **PolySwitch[®] Resettable PPTCs** Surface Mount > SMDC Series **==> picture [93 x 32] intentionally omitted <==** ## **Part Ordering Number System** **==> picture [106 x 12] intentionally omitted <==** **----- Start of picture text -----**<br> SMDC 125 F /33 -2<br>**----- End of picture text -----**<br> **==> picture [109 x 56] intentionally omitted <==** **----- Start of picture text -----**<br> Packaging<br> 2 = Tape and Reel<br>Alternative Voltage Rating (If Applicable)<br>Lead Free<br>Hold Current Indicator<br>**----- End of picture text -----**<br> **==> picture [40 x 6] intentionally omitted <==** **----- Start of picture text -----**<br> Product Series<br>**----- End of picture text -----**<br> ## **Solder Reflow Recommendations** **==> picture [245 x 188] intentionally omitted <==** **----- Start of picture text -----**<br> Profile Feature Pb-Free Assembly<br>Average ramp up rate (TsMAX to Tp) 3°C/s max<br>Preheat -<br>• Temperature min (TsMIN) 150°C<br>• Temperature max (TsMAX) 200°C<br>• Time (tsMIN to tsMAX) 60-120 s<br>Time maintained above: -<br>• Temperature (TL) 217°C<br>• Time (tL) 60-150 s<br>Peak/Classification temperature (Tp) 260°C<br>-<br>Time within 5°C of actual peak temperature<br>Time (tp) 30 s max<br>Ramp down rate 3°C/s max<br>Time 25°C to peak temperature 8 min max<br>**----- End of picture text -----**<br> **==> picture [243 x 144] intentionally omitted <==** **----- Start of picture text -----**<br> tp<br>Tp Critical Zone<br>Ramp Up TL to Tp<br>TL TsMAX tL<br>TsMIN<br>ts<br>Preheat Ramp Down<br>25<br>t 25˚C to Peak<br>Reflow Profile Time<br>Temperature<br>**----- End of picture text -----**<br> **Note:** All temperatures refer to topside of the package, measured on the package body surface. ## **Solder Reflow** - Recommended reflow method: IR, hot air, nitrogen. - Recommended maximum paste thickness: 0.25mm (0.010in) - Devices can be cleaned using standard methods and aqueous solvents. - Experience has shown the optimum conditions for forming acceptable solder fillets occur when a reasonable amount of solder paste is placed underneath each device’s termination. As such, we request that customers comply with our recommended solder pad layouts. - Customer should validate that the solder paste amount and reflow recommendations meet its application. - We request that customer board layouts refrain from placing raised features (e.g. vias, nomenclature, traces, etc.) underneath PolySwitch devices. It is possible that raised features could negatively impact solderability performance of our devices. ## **Rework** • Standard industry practices. (Please also avoid direct contact to the device.) © 2020 Littelfuse, Inc. Specifications are subject to change without notice. Revised: BA.09/30/20 **PolySwitch[®] Resettable PPTCs** Surface Mount > SMDC Series **==> picture [93 x 32] intentionally omitted <==** ## **Tape and Reel Specifications** **==> picture [506 x 225] intentionally omitted <==** **----- Start of picture text -----**<br> SMDC, EIA 481-1<br>Description SMDC030F, SMDC050F, SMDC185F/33,<br>SMDC310F/18<br>SMDC075F, SMDC125F/33 SMDC300F/24<br>W 16.0 ± 0.30 16.0 ± 0.30 16.0 ± 0.30<br>P0 4.0 ± 0.10 4.0 ± 0.10 4.0 ± 0.10<br>P1 8.0 ± 0.10 8.0 ± 0.10 8.0 ± 0.10<br>P2 2.0 ± 0.10 2.0 ± 0.10 2.0 ± 0.10<br>A0 5.5 ± 0.1 5.35 ± 0.1 5.5 ± 0.1<br>B0 7.9 ± 0.1 7.85 ± 0.1 8.0 ± 0.1<br>B1 max 12.1 12.1 12.1<br>D0 1.5 + 0.10/ -.00 1.5 + 0.10/ -.00 1.5 + 0.10/ -.00<br>F 7.50 ± 0.10 7.50 ± 0.10 7.50 ± 0.10<br>E1 1.75 ± 0.10 1.75 ± 0.10 1.75 ± 0.10<br>E2 min 14.25 14.25 14.25<br>T max 0.35 0.35 0.35<br>T1 max 0.1 0.1 0.1<br>K0 0.9 ± 0.1 1.45 ± 0.1 2.0 ± 0.1<br>A max 330 330 330<br>N min 50 50 50<br>W1 16.4 + 2.0/-.00 16.4 + 2.0/-.00 16.4 + 2.0/-.00<br>W2 max 22.4 22.4 22.4<br>**----- End of picture text -----**<br> ## **Tape and Reel Diagrams** **==> picture [343 x 256] intentionally omitted <==** **----- Start of picture text -----**<br> T<br>Cover Tape P 0<br>P2 D0<br>E1<br>F<br>W<br>B1 K0 B0 E2<br>T1<br>Embossment A 0 P 1<br>Center lines<br>Figure 1 of cavity<br>W2 (Measured at Hub)<br>Cover Tape A N (Hub Dia.)<br>Carrier Tape W1 (Measured at Hub)<br>Embossed Cavity<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. © 2020 Littelfuse, Inc. Specifications are subject to change without notice. Revised: BA.09/30/20
Updated at April 12, 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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