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- 12A (Small) SFJ Series
Secondary protection fuse
12A (Small) SFJ Series
Suitable for compact and slimline mobile devices.
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- Product name
- SFJ-0412 / SFJ-0812 / SFJ-1212 / SFJ-1412
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- Features
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- Achieving a low height of 0.85 mm. Suitable for compact and slimline mobile devices.
- Protects Li-ion batteries from overcharging (overvoltage) and overcurrent.
- When overcharging occurs, the fuse element melts to shut off the circuit, and simultaneously the power to the heater is also cut off.
- Placing a heater directly under the fuse element breaks the circuit quickly.

Related articles
Specifications
| Product name | SFJ-0412 | SFJ-0812 | SFJ-1212 | SFJ-1412 |
|---|---|---|---|---|
| Applicable cells in series | 1 cell | 2 cells | 3 cells | 4 cells |
| Rated current (A) | 12 | |||
| Rated voltage (VDC)*1/ Rated breaking capacity (A) |
36/50 (UL/TUV) 48/200, 25/250 (UL) |
|||
| Operating voltage (V) | 3.0 to 5.5 | 4.0 to 9.0 | 7.4 to 13.8 | 10.5 to 19.6 |
| Heater resistance (Ω) | 1.0 to 1.5 | 2.0 to 3.2 | 5.7 to 9.9 | 11.2 to 20.0 |
| Fuse resistance (mΩ) | 2.4 | |||
| Dimension (mm)*2 | 4.0 x 3.0 x 0.85 (See below diagram) | |||
- *1 Maximum voltage at which cutoff of the fuse is possible. It is not the operating voltage for the heater.
UL certification: File No. E167588
TUV certification: Certificate No. J9650637
RoHS directive: Conforming - *2 Values without tolerance indications are nominal values.
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Suitable for Li-ion battery pack for smartphones, tablet PCs, notebook PCs, cordless power tools, storage batteries, power-assisted bicycles, electric motorcycles, and other similar battery powered devices.
caution
Note on the characteristic data given - Data on the characteristics of the products described in this page based on the results of evaluations carried out by the company. This does not guarantee that the characteristics of the product conform with your usage environment. Before use, review the usage conditions based on evaluation data obtained from the equipment and substrates actually used.
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