Toshiba has announced a new line of eFuse IC products to provide a range of monitoring and protection mechanisms for power supply applications. The range of devices includes six products from the TCKE8xx series, which offer various protection functions for power supplies.
Unlike traditional fuses, eFuses are resettable. In addition to the short-circuit protection, they also provide overcurrent limiting with an accuracy of ±11%, overvoltage and over-temperature protection. The ICs are available in a 3 x3 x 0.75 mm WSON10B package and offer a typical RON of 28 mΩ. Input voltages from 4.4 to 18 V and load currents up to 5 A are supported.
According to Toshiba, its TCKE8xx ICs have advantages over more traditional circuit protection devices such as positive temperature coefficient (PPTC) resettable polymer fuses. They respond much faster, can be reset directly via a logic signal and retain their low on-resistance even after multiple trip events.
Typical application example of a TCKE8xx-eFuse. Image: Toshiba.

The eFuses of the TCKE8xx series are offered in three categories: without overvoltage protection, 5 V (VOVC = 6.04 V) and 12 V (VOVC = 15.1 V). Each overvoltage category is also offered with auto-retry or latched reaction to a fault event. Recovery from a latched safety state is via an external control input.
The integrated comparator is able to switch off the output within 150 ns of fault-event detection. An external capacitor can be fitted to reduce peak inrush current to the load by setting the output slew rate as required.
An external N-channel MOSFET can be used to provide reverse current protection.
The small format and low on-resistance of the eFuses makes them suitable for use in a wide range of applications. The TCKE8xx series is certified to IEC 62368-1.