Today I got some parts, including the LD1086D2T33TR regulator chips. I connected ground to ground and 24V to the input pin and I expected 3.3V on the output pin but what I got was my bench power supply going into constant current mode (limiting at approx 1A) and a reduction in voltage from the bench power supply output to about 8.5V instead of the 24V that I had set it to?
The output of the regulator started at about 6V and very steadily grew... I stopped this test when the output pin reached about 6.2V.
I am utterly bemused and didn't expect this behaviour at all - I expected that the regulator would accept 24V in and give 3.3V out, the only thing happening that I did expect, is that the regulator gets real warm.
Does anyone have any idea what is happening here?