Ideal Diode Bridge Controller Reduces Rectifier Heat/Voltage Loss
June 13, 2013
Ideal diode bridge controller for 9 V to 72 V systems replaces each of the four diodes in a full-wave bridge rectifier with a low loss N-channel MOSFET.
The LT4320 from Linear Technology is an ideal diode bridge controller for 9 V to 72 V systems that replaces each of the four diodes in a full-wave bridge rectifier with a low loss N-channel MOSFET to reduce the power dissipation and increase available voltage. Power supply size is reduced as the enhanced power efficiency eliminates bulky heat sinks. Low voltage applications benefit from the extra margin afforded by saving the two diode drops inherent in diode bridges. An integrated charge pump provides the gate drive for the external low on-resistance N-channel MOSFETs without requiring external capacitors. The controller is available in two options, the LT4320, designed for dc to 60 Hz voltage rectification, and the LT4320-1 which rectifies dc to 600 Hz. Specified over the -40°C to 85°C industrial temperature range, the controller is offered in an 8-pin 3 x 3 mm DFN package, and a 12-lead MSOP package with enhanced high-voltage pin spacing. Available now, prices begin at $2.95 each/1,000.
