DC1823B - Schematic2/10/2016
Demonstration circuit 1823B features the LT4320, an ideal diode bridge controller suitable for applications that require high current AC to DC full-wave rectification or DC polarity correction. With an AC input, the input voltage range is 12VAC to 24VAC, the output voltage can be as high as 70V, and the output current can be as high as 1.5A. The AC current is limited by the capacitance provided on the demo board and can be increased up to 17A with additional load capacitance. The DC input voltage range is 9V up to 40V, and the maximum DC output current is 30A.
The LT4320 drives four N-channel MOSFETs to perform full-wave rectification functionally similar to a discrete diode bridge but with much lower power dissipation. This topology eases thermal design, and increases usable output voltage. In addition, an all N-channel topology has benefits over a P-channel topology such as a wider selection of MOSFETs, lower cost, lower RDS(ON), and smaller footprint.