MM103J1F
NTC Thermistor, 10 kohm, 3892 K, SMD, -55 °C to 220 °C, MM Series
- Manufacturer: LITTELFUSE
- Product type:
- SVHC: To Be Advised
- B-Constant: 3892K
- Lead Length: -
- NTC Mounting: Surface Mount
- NTC Case Size: SOD-80
- Product Range: MM Series
- Qualification: -
- Probe Diameter: -
- Probe Material: -
- Thermistor Type: Chip
- Resistance (25°C): 10kohm
- Thermistor Mounting: SMD
- B-Constant Tolerance: -
- Operating Temperature Max: 220°C
- Operating Temperature Min: -55°C
- Resistance Tolerance (25°C): ± 1%
- Thermal Time Constant (in Air): 5s
| Delivery and price | |
|---|---|
| Units per pack | 250 |
| Price | 0.664 € |
| Current stock | 10+ |
| Lead time | 30 days |
**Surface Mount Thermistors** MELF Style Thermistor ## MM Series LL-31 MicroMELF T ~~hermistors~~ ## **Description** Littelfuse LL-31 “MicroMELF” style glass encapsulated surface mount thermistors are manufactured using super stable NTC chips which are hermetically sealed in a glass package. The result is a device which exhibits excellent long-term reliability and stability even when subjected to severe environmental or thermal conditions. Their uniform dimensions make them especially suitable for use with automatic insertion equipment. ## **Options** - [Non-standard ] •[Point matched at ] resistance values specified temperatures and tolerances - [Tape and Reel ] Packaging ## **Dimensions** ## **Features** **==> picture [232 x 93] intentionally omitted <==** **----- Start of picture text -----**<br> B<br>w oo<br>TINNED<br>DUMET<br>A CONTACT<br> TABS<br>¥©O C [Flr<br>n o GLASS<br>BODY<br>**----- End of picture text -----**<br> - [High temperature ] capability to +220°C - [ Low cost] - [Excellent long-term ] stability - [Surface mountable] - [Hermetically sealed ] glass package ## **Part Numbering System** ## Dimensions shown in inches. |**A**<br>0.049”<br>± 0.004”|**B**<br>0.075”<br>± 0.008”|**C**<br>0.053”<br>Nom| |---|---|---| **==> picture [222 x 99] intentionally omitted <==** **----- Start of picture text -----**<br> MM 10 3 E 1 K<br>Series Resistance Tolerance<br>F = ±1%<br>Resistance @ 25ºC K = ±10%<br>Base Value No Significance<br>Multiplier, power of 10 AE R-T Curve<br>Ex. 103 = 10 Ω x 10 [3 ] = 10,000 Ω<br>**----- End of picture text -----**<br> Note: Not all combinations of Part Number codes are available. Contact Littelfuse for details. © 2018 Littelfuse, Inc. Revised: February 26, 2018 Specifications are subject to change without notice. littelfuse.com **1** **Surface Mount Thermistors** MELF Style Thermistor ## MM Series LL-31 MicroMELF T ~~hermistors~~ ## **Specifications** |Part<br>Number|Resistance<br>Ohms<br>@25°C|*Resistance<br>Tol. ± % @<br>25°C|Accuracy<br>(±ºC)<br>0-50ºC|R-T<br>Curve|Temperature<br>Coefficient<br>(% / °C)<br>@ 25°C|Beta (K)<br>0-50°C|Dissipation<br>Constant,<br>Nominal<br>(mW/°C)|Thermal<br>Time<br>Constant,<br>Max. -<br>Still Air<br>(seconds)|Temperature<br>Rating<br>(°C)| |---|---|---|---|---|---|---|---|---|---| |MM222E1K|2186|10|±0.5°C|E1|-3.82|3320|1|5|-55 to +220| |MM302F1K|3000|10|±0.5°C|F|-3.86|3419|1|5|-55 to +220| |MM502F1K|5000|10|±0.5°C|F|-3.86|3419|1|5|-55 to +220| |MM103E1K|10000|10|_|E1|-3.82|3320|1|5|-55 to +220| |MM103G1K|10000|10|_|G|-4.03|3575|1|5|-55 to +220| |MM103J1F|10000|1|_|J|-4.4|3892|1|5|-55 to +220| |MM103J1K|10000|10|_|J|-4.4|3892|1|5|-55 to +220| |MM153J1K|15000|10|_|J|-4.4|3892|1|5|-55 to +220| |MM203J1F|20000|1|_|J|-4.4|3892|1|5|-55 to +220| |MM203J1K|20000|10|±0.5°C|J|-4.4|3892|1|5|-55 to +220| |MM104J1F|100000|1|_|J|-4.4|3892|1|5|-55 to +220| |MM104J1K|100000|10|_|J|-4.4|3892|1|5|-55 to +220| |MM104R1K|100000|10|_|R|-4.68|4140|1|5|-55 to +220| |MM254R1K|250000|10|±0.5°C|R|-4.68|4140|1|5|-55 to +220| *Resistance tolerances of ± 1%, 2%, and 5% are available upon request |**Packaging**|||| |---|---|---|---| |Packaging Option|Packaging Code|Standard Quantity|Standard| |Tape and Reel|-TR|2500|EIA-481| **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. Revised: February 26, 2018 Specifications are subject to change without notice. littelfuse.com **2**
Updated at June 8, 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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