I'm really trying to understand my voltage regulator (LM350T), but I think I'm still missing a few things. If I add cap C3 (I've tried 0.1uF and 10uF) to the output in the circuit below (note that the regulator should be LM350T), I get a rapid voltage rise (e.g. from 11V to 16.36V, or 6.4V to 9.8V), then a verrrry slow drop after that.
This shouldn't be right: the cap is not "part of" the regulator circuit in that it doesn't pass information between the adjust and out pins as far as I can see. The effect I describe should be in the capacitor itself across the plates, not in the regulator output. So I don't think it should have any effect. But it does.
Beyond that, it increases my minimum voltage out from ~1.25V to nearly 1.5V, and this doesn't appear to be discussed in the datasheet. I mean, I guess they don't have to include in the applications that the addition of an output cap will significantly change the minimum circuit voltage, but it seems like the TI sheet would have at least mentioned it, as it is very complete otherwise.