Diodes has introduced an active OR’ing controller chip which it claims can be used to replace heat-dissipating blocking diodes with high efficiency mosfets.

The aim is to offer cooler running and higher reliability operation.

The heat dissipated by the Schottky blocking diodes traditionally used to protect a load from faulty power supplies is high, relating directly to its 0.5V forward voltage drop.

Replacing the diodes with low on-resistance mosfets, with typical forward voltages of under 100mV, means power dissipation is reduced.

The ZXGD3102 is therefore purpose designed to control mosfets in high-reliability N+1 redundant power systems.

Sinking a peak turn-off current of 5A, the controller’s gate drive is able to achieve a typical mosfet turn-off time of 160ns, ensuring the rapid load protection that’s needed to avoid any variation in bus voltage in the event of a power supply failure and hot-swapping. 

The chip is housed in the compact SM8 package and requires a minimal external component count.  It uses a 5 to 15V low current bias rail, which is easily derived using a miniature zener diode.

More information: www.diodes.com