I had a TEM2 box on my workbench, to futz with firmware, and figured that, since I had all the gear handy, I'd check the transient response of the LDO that we'd been having such a friendly discussion about.
This was the circuit, the 1.2 and 1.1 supplies:
I cranked up a function generator to make a 5 volt p-p square wave, and capacitively coupled that into TP46. So I was poking 100 mA current steps into the LDO output.
I had to external trigger and signal average to get the noise down, at
5 mv/div and a 1:1 probe.TP47..50 are current shunts. U70 was obviously manufactured in Italy.
Load step at TP46:
and the gate drive...
Yup, it's a bit underdamped, about what the LT Spice sim predicted. It sure doesn't do anything radical.
I could add some resistors in series with C247 and C250 next time, to improve damping, but it doesn't really matter. The transient bump is only 9 mv, and the ringing is a lot smaller than that.
Well, that was fun. Back to firmware....