We use these regulators quite frequently in RC aircraft. Recently I have seen several where the voltage output is only 3v. The input voltage is 16.8v to ~11.4v depending on battery used. If I try to power it with 16.8v to around 13v it will only output 3v 95% of the time. Occasionally it will power to 12v. But if I give it 12.6 to 11.4 it outputs 12v correctly every time.
Any Idea how to get them to work properly every time. I always run with the SHDN pin shorted to VIN, and even tried without, and no difference in performance.
Completed some more testing. It appears the camera and video transmitter are overdrawing the unit on start up. It looks like I will have to start using 600 mA-1A units now. Oddly enough, a unit that was a year old works fine, but the newer ones dont appear to be able to handle the load as well.
I am glad you were able to figure it out. Thanks for letting us know what the issue was. It doesn’t seem that unexpected to me that you would have some boards that behave differently than others, since in that situation it sounds like the regulators are being used outside their specifications, so the behavior is unpredictable.