DESCRIPTION
The LTC®4370 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 VCC pin. 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.

FEATURES
■ Shares Load Between Two Supplies
■ Eliminates Need for Active Control of Input Supplies
■ No Share Bus Required
■ Blocks Reverse Current
■ No Shoot-Through Current During Start-Up or Faults
■ 0V to 18V High Side Operation
■ Enable Inputs
■ MOSFET On Status Outputs
■ Dual Ideal Diode Mode
■ 16-Lead DFN (4mm × 3mm) and MSOP Packages

APPLICATIONS
■ Redundant Power Supplies
■ High Availability Systems and Servers
■ Telecom and Network Infrastructure