Analog Devices Inc./Maxim Integrated

The LTC4370 is a two-supply current sharing controller which incorporates MOSFET ideal diodes. The diodes block reverse and shoot-through currents during start-up and fault conditions. Their forward voltage is adjusted to share the load currents between supplies. Unlike other sharing methods, neither a share bus nor trim pins on the supply are required.The maximum MOSFET voltage drop can be set with a resistor. A fast gate turn-on reduces the load voltage droop during supply switchover. If the input supply fails or is shorted, a fast turn-off minimizes reverse current transients.The controller operates with supplies from 2.9V to 18V. For lower rail voltages, an external supply is needed at the VCCpin. Enable inputs can be used to turn off the MOSFET and put the controller in a low current state. Status outputs indicate whether the MOSFETs are on or off. The load sharing function can be disabled to turn the LTC4370 into a dual ideal diode controller.ApplicationsRedundant Power SuppliesHigh Availability Systems and ServersTelecom and Network Infrastructure

The LTC4372/LTC4373are positive high voltage ideal diode controllers that drive an external N-channel MOSFET to replace a Schottky diode. They control the forward voltage drop across the MOSFET to ensure current delivery or current transfer from one path to the other even at light loads.A 5μA operating current achieves high efficiency for intermittent load applications or always-on backup power supplies. If a power source fails or is shorted, a fast turn-off minimizes reverse current transients. The LTC4372/LTC4373 control back-to-back N-channel MOSFETs for inrush current control and load switching.The LTC4372’s SHDN pin keeps the MOSFET off and reduces the quiescent current to 3.5μA. The LTC4373 has a UV pin for undervoltage monitoring while theUVOUTpin provides hysteresis adjustment and status information. During undervoltage, the back-to-back MOSFETs are cut off and quiescent current reduces to 0.5μA.APPLICATIONSAutomotive Battery ProtectionRedundant Power SuppliesPortable InstrumentationSolar Powered SystemsEnergy Harvesting ApplicationsSupply Holdup