OR’ing controller manages power supply sharing, raises UPS reliability

November 20, 2014 // By Graham Prophet
Diodes Inc. has a 40V-rated active OR’ing controller intended to raise the reliability of uninterruptible power supplies (UPS) in telecom, data centres and server installations.

The ZXGD3108N8 is designed to fully enhance very low RDS(ON) power MOSFETs, enabling lossy Schottky blocking diodes to be replaced and resulting in lowered operating temperature and increased UPS system integrity.

By driving MOSFETs in this way, the controller also improves the overall system efficiency of standard 12V and 24V common rail systems. Compared to alternative devices, the ZXGD3108N8 offers the lowest turn-off threshold voltage. At less than -3 mV, and with a tight tolerance of ±2 mV, system stability and efficiency is improved under light load conditions.

The controller is able to sink a current of 5A, ensuring the fastest possible discharge of the paralleled OR'ing MOSFETs. At 600 nsec, turn-off is fast to avoid reverse-current flow and prevent voltage dropping on the common rail. In a typical 12V configuration, device quiescent current is specified as sub-400 µA and standby power consumption less than 5 mW.

Provided in the SO-8 package, the ZXGD3108N8 OR’ing MOSFET controller is priced at $1 (1000).

Diodes; www.diodes.com