Geneva, Switzerland: STMicroelectronics has rolled out a family of hot-swap power-management devices that will help reduce ownership costs for important equipment such as storage devices, computers, USB accessories, enterprise systems, appliances, and home electronics.
The first two devices in the family provide smart over-voltage and over-current protection for 5-V and 12-V electronics. The STEF05 and STEF12 are electronic fuses in 3- by 3-mm IC packages, which can replace larger conventional fuses or other protection devices such as transils or diodes (see the figure). Unlike fuses, they do not cut the power suddenly or require replacement after actuating, helping to improve equipment uptime and availability while reducing maintenance costs. Compared to transils or diodes, these electronic fuses enable versatile and simple programming of protection parameters.
If a fault occurs, the electronic fuse restricts the current supplied, protecting the connected circuitry, and ultimately turns the protected equipment off if the fault persists. It can be reset by a signal from the system or by restarting the power supply. The device provides a signal when it is intervening, allowing the system to generate a warning. If the fault persists after the reset, the fuse immediately limits the current and turns off again to protect the circuitry.
The devices also integrate circuitry that limits voltage fluctuations applied to the protected load, as well as programmable startup time, enabling use in hot-swappable modules for equipment such as enterprise servers, storage, or telecom systems. Hot-swapping allows faulty modules to be replaced without fully powering down the system, minimizing disruption to services.