Linear Technology/Analog Devices’ LT8672 is an active rectifier controller for reverse input protection. This controller drives an external N-channel MOSFET to replace a power Schottky diode. Its very low quiescent current and fast transient response meet the tough requirements in automotive applications where AC input signals of up to 100 kHz are present. These signals are rectified with minimum power dissipation on the external FET, simplifying thermal management on the PCB.
With a drop of only 20 mV, the LT8672 solution eases the minimum input voltage requirement during cold crank and start-stop, allowing simpler and more efficient circuits. If the input power source fails or is shorted, a fast turn-off minimizes reverse current transients. An available shutdown mode reduces the quiescent current to 3.5 μA. An integrated auxiliary boost regulator provides the required boost voltage to turn the external FET fully on. A power good pin signals when the external FET is ready to take load current. The LT8672 was designed automotive battery protection, industrial power supplies, and portable instrumentation applications.