Ideal Diode Bridge

Linear Technology’s pioneering Ideal Diode Bridge Controllers replace each of the four diodes in a full-wave bridge rectifier with a low-loss MOSFET to drastically reduce the power dissipated, heat generated and voltage drop. The conventional Schottky diode bridge rectifier is a classic circuit employed for full-wave AC-to-DC rectification and DC polarity correction. Due to the approximate 0.6V drop of each diode, the two diodes in the input-to-output path dissipate power (1.2W per Ampere), radiate heat, raise the ambient temperature, and complicate thermal design. At low input voltages, the two diode drops significantly reduce the voltage available to the downstream DC/DC converter. Both the heat and voltage-loss problems are solved by an Ideal Diode Bridge (also called an active diode bridge). Heat sinking requirements are either eliminated or reduced, shrinking the overall footprint and providing significant cost savings. Power saved enhances conversion efficiency and lowers operating costs.

The LT4320/LT4320-1 ideal diode bridge controller is designed for input frequencies from DC to 60Hz/600Hz, and operates with rectified outputs from 9V to 72V, supporting 24VAC, 32VAC and a wide variety of DC applications, but not 3-phase designs. A strong integrated charge-pump enables a simple, all N-channel MOSFET design. Please click the blue button below to view a parametric table of all Ideal Diode Bridge controllers.

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