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When using 2 PSs for redundancy purposes we connect positive outputs through diodes, as I understand. Is it possible to connect voltage feedback network of the buck converter to diodes cathode, to let the IC compensate diodes voltage drop?

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  • \$\begingroup\$ Depends. Your diode is literally one-way, so the "slope" of your voltage ripple looks a bit different. Sometimes this upsets your regulation loop at light load. \$\endgroup\$
    – winny
    Commented Sep 14, 2017 at 16:23
  • \$\begingroup\$ You think a better way will be to connect feedback network to anode and tune the voltage counting diode drop? \$\endgroup\$
    – Roman Simonyan
    Commented Sep 14, 2017 at 16:25
  • \$\begingroup\$ Again, it depends. You will regain stability for some converters but loose some load regulation. If your loop on the other hand is happy all over the load range after the diode, go for it. How will you do load sharing? \$\endgroup\$
    – winny
    Commented Sep 14, 2017 at 16:30
  • \$\begingroup\$ I need redundancy. I plan just to connect both PSs. My load will be max 0.5A, PSs can do 2A. \$\endgroup\$
    – Roman Simonyan
    Commented Sep 14, 2017 at 16:32
  • \$\begingroup\$ Good. Then it should be just the loop stability you need to worry about. \$\endgroup\$
    – winny
    Commented Sep 14, 2017 at 16:41

1 Answer 1

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If you need a switch without voltage drop, you need to use ICs that implement so-called "ideal diodes", look at "intelliMAX" line of switches from Fairchild/ONsemi, like FPF1320. See a bit longer answer here.

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