Diodes Inc. Introduces OR’ing Controller For Shared Power Systems
Diodes Inc. announced an active OR’ing controller chip, enabling shared power system designers to replace heat-dissipating blocking diodes with high efficiency MOSFETs. The ZXGD3102 is said to ensure cool running, low maintenance and high reliability operation in up-time critical telecom, server and mainframe applications.
The high heat dissipated by Schottky blocking diodes, traditionally used to protect a load from faulty power supplies, relates directly to the hefty 0.5V forward voltage drop. Replacing the diodes with low on-resistance MOSFETs, which have typical forward voltages of under 100mV, means that power dissipation is greatly reduced. The ZXGD3102 is specifically 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 is needed to avoid any variation in bus voltage in the event of a power supply failure and hot-swapping. To meet the fault handling requirements, turn-on time can be adjusted to enable a smooth handover between supplies. The ZXGD3102’s input voltage blocking capability is 180V.
The ZXGD3102 is housed in the compact SM8 package and requires a minimal external component count. The ZXGD3102 uses a 5 to 15V low-current bias rail, which is easily derived using a miniature zener diode.
