Ideal Diode Controller

[Christopher]

All.

I need to switch between a fixed 48V Source (V1, coming from a ACDC PSU) and a variable 20-60V Source (V2, coming from bench supply) at a maximum current of 10A. No high frequency, just manually switching every ~30 seconds at the minimum.

I have come up with the following circuit which works! But I need to be able to choose between the sources rather than the standard diode-or configuration.


Obviously a Shottky diode is pretty much out of the question (10A*0.6V=6W Loss). A relay and other mechanical devices are also out of the question due to arcing.


What is driving the gates of M1&M2 in the LTC4355? Can I reproduce this easily?

[Christopher]

Using a bootstrapped gate seems to be the way to go..

This *should* work from my app note reading skills, but LTSpice is reporting a wacky high power dissipation in M1.. Can you spot what it is?

EDIT: Seems to work with a resistor instead of a constant current load in ltspice!