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App note: Advantages of eFuses versus PTC resettable fuses

App note: Advantages of eFuses versus PTC resettable fuses

The advantage of eFuses an application note from ON Semiconductors. Link here (PDF)

Overcurrent protection is a basic necessity for electrical devices. While many people are familiar with fuses and household circuit breakers, few are intimately familiar with the kinds of overcurrent protection devices that are found in electronics.

Though not a comprehensive list, there are basically three types of overcurrent protection devices in electronics. In order of increasing sophistication they are:
• One−shot fuses
• Positive temperature coefficient (PTC) resettable fuses
• Electronic fuses (eFuses)


In many cases, a PTC may provide adequate protection. Its response should be fast enough to prevent burn damage to wiring. In addition, its ability to maintain voltage levels in response to a fault can be enhanced by choosing a higher current supply, or perhaps even adding decoupling capacitance on the power supply (input) side.
However, in other cases an eFuse is not only a better choice but its superior performance and features are required to satisfy application requirements. The use of an eFuse may also save cost and board space if additional circuitry, needed to prevent inrush currents or to provide overvoltage protection, can be eliminated by using an eFuse.