Ideal diode bridge controller minimizes rectifier heat

The LT4320 is a first of its kind ideal diode bridge controller that targets 9 to 72-V systems and replaces each of the four diodes in a full-wave bridge rectifier with an n-channel MOSFET. It helps reduce power dissipation and increase available voltage. The diode bridge power dissipation is 1.2 W at 1 A, 12 W at 10 A, and 120 W at 100 A.

The controller operates from dc to 600 Hz or dc to 60 Hz. The LT4320 switch control turns on the appropriate two MOSFETs, while keeping the other two off to prevent reverse currents. An integrated charge pump provides the gate drive for the external low on-resistance n-channel MOSFETs without requiring external capacitors. Specified over the −40°C to 85°C industrial temperature range, the device is offered in an eight-pin 3 x 3-mm DFN package, and a 12-lead MSOP package with enhanced high-voltage pin spacing. Evaluation circuit boards are also available.