This document introduces Linear Technology's ideal diode controller, which can operate over a 0V to 18V input voltage range and has a zero forward voltage drop. The controller can be used as a replacement for Schottky diodes and can save power and space.
The LTC4352 is an ideal diode controller designed for use with 0V to 18V input supplies. It works in tandem with an N-channel MOSFET to create a near-ideal diode, replacing traditional Schottky diodes to save power and PCB space by reducing forward voltage drop.
The device employs a linear control method rather than hysteretic comparison to maintain a constant 25mV forward voltage drop across the MOSFET. This approach avoids issues with light load currents and DC reverse current found in comparator-based techniques. Additionally, it features fast switch control for rapid transient response during supply switchover events.
The LTC4352 is designed to operate with input supplies ranging from 0V to 18V.
The LTC4352 servos the gate of the MOSFET to maintain a forward voltage drop of 25mV.
The device flags a fault if it senses more than 250mV of forward voltage drop across the MOSFET.