I posted this as part of a previous note:  Is anyone aware of an integrated single channel synchronous rectifier ?  I want to turn on a MosFET whenever the parasitic diode is forward biased, then off when the voltage drops to zero or reverses.  I understand that it would require an auxiliary PSU for detection and gate-drive.

TIA

You could check out the LTC4358 ideal diode at https://www.analog.com/en/products/ltc4358.html

They have other ideal diode controller parts described in this brochure https://www.analog.com/media/en/news-marketing-col...

You might look at the LT8309 synchronous rectifier controller (no integrated FET) in a SOT-23 package. https://www.analog.com/en/products/lt8309.html

Yay.  Thanks.  A matter of knowing what the manufacturer calls them.  Unfortunately, no high current internal FET ones, but it is a good start.

Other possibility at Diodes Inc 

https://www.diodes.com/part/view/DZDH0401DW?BackID...

https://www.diodes.com/products/power-management/a...