Electronic Fuse Hot Swaps in 12-V Systems

A new member of the SMART HotPlug family, ON Semiconductor’s NIS5112 is an integrated self-protected, resettable, electronic fuse that utilizes a high side N-channel FET, driven by an internal charge pump. Designed for use in 12-V systems, the electronic fuse provides a cost-effective inrush current limiting solution for hot-swap applications.

Designed to allow the safe insertion and removal of equipment into 12-V backplanes, the NIS5112 utilizes an internal SENSEFET that enables active current limiting via inexpensive chip resistors instead of more expensive, low-impedance current shunts. The device has a typical on resistance of 30 mΩ.

The NIS5112 has an input voltage range of 9 V to 18 V and also provides overvoltage protection intended to allow operation through transients while protecting the load. This device also contains circuits to control the turn-on voltage, output current, die temperature, turn-on di/dt and turn-on dV/dt, as well as an enable/timer function. It offers robust thermal protection circuit in two different thermal limit versions, auto-retry and latch off.

The NIS5112D1R2G (Latch) and NIS5112D2R2G (Retry) are offered in a lead free, SO-8 package and priced at $1.15 per unit in 2,500 unit quantities. Samples are available.