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Next day of troubleshooting and im resoldering all the fets to see if thats the problem, because aside from the power supply mux fets seemingly turning on for only aux input, there doesnt seem to be an LTC problem from the above numbers. I am finding that soldering down the fets is incredibly difficult because of how large the associated poly pours and copper is. For next rev, we might want to minimize the poly pours by recording how much they heat up from this testing and adjusting accordingly.
YES it finally works 😃 turns out it was a fet soldering problem, look at the above^
i tested priority between dcdc and aux, and dcdc always takes priority which is good. Something else that josh wanted to test was the switchover time from output turning on to input being supplied. I used the scope to plot both input and output and compare timing. See below for a difference of about 300ms from aux on to output
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below is the switchover time from DCDC to output. The small difference from aux to DCDC seems negligible.
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weird update, all of a sudden, my controller board stopped blinking its led (meaning something was wrong) and started becoming extremely hot when plugged into my laptop. I probed across 3V3 and gnd and see that now its shorted on the controller board. something must have happend during my testing to somehow short 3V3 to gnd with my controller attached, thus damaging the CB and most likely the MCU. In addition, for some reason the LTC seems to not work properly because it is able to turn on the output without a 3V3 reference, which should not happen. After waiting a couple of minutes and trying again, it seems that this is not the case, and the bulk capacitor was probably the reason I was still seeing output on the LTC as it was holding the 12V for a bit longer.