The LTC?4352 creates a near-ideal diode using an external
N-channel MOSFET. It replaces a high power Schottky
diode and the associated heat sink, saving power and
board area. The ideal diode function permits low loss
power ORing and supply holdup applications.
The LTC4352 regulates the forward voltage drop across
the MOSFET to ensure smooth current transfer in diode-OR
applications. A fast turn-on reduces the load voltage droop
during supply switch-over. If the input supply fails or is
shorted, a fast turn-off minimizes reverse currents.
The controller operates with supplies from 2.9V to 18V.
For lower voltages, an external supply is needed at the
VCC pin. Power passage is disabled during undervoltage
or overvoltage conditions. The controller also features an
open MOSFET detect circuit that fl ags excessive voltage
drop across the pass transistor in the on state. A REV pin
enables reverse current, overriding the diode behavior
when desired.