I have planned to build a variable voltage DC power supply based on the LTC3780 DC-DC 5-32V converter. I guess you are familiar with the converter, but I am attaching and image for illustration:
I used an AC/DC adapter (12V, 4A) on the input. Everything worked, so I replaced the default trimmers with potentiometers. It should have a 500kΩ pot on Vout set and a 200KΩ pot on current limit set.
I tested it and quickly realized that I am getting just 13V output max. (with 12V input). I made a stupid mistake - I switched the pots, so 500kΩ was on current set and 200kΩ on Vout set.
So I connected the potentiometers as they should be and everything worked fine, for a while. Then I saw the green "OK" LED was randomly blinking from bright to nearly off (which indicates high and low Vout). I disconnected the input, connected it again and realized that the red FAULT diode is on and the LTC3780 IC is geting REALLY HOT.
I desoldered the potentiometers and replaced them back with original trimmers, just to be sure there is no additional failure there. But nothing changed - FAULT is still on and the IC gets hot in a second.
Is there anything I could inspect to identify the problem, or did I just fry the LTC3780 by using the wrong pots? I will be happy for every suggestion how to possibly fix it, as I already made nice wooden box for it... :(