Other Parts Discussed in Thread: LP5912,
I've used TI's web utility to select components for outputting 5v from the TPS54308. That 5v then supplies an ldo ( LP5912 ) to step down to 3.3v. That's all well and good.
The issue I'm having is that when I try to disable the regulator, the output only drops to 2.5v instead of 0v. And since I have the ENA pin of the LP5912 tied to the same 5v signal, it too outputs 2.5v.
I'm driving the enable pin directly from the microprocessor. I've tried adding an external pull-down on that pin thinking that perhaps the microprocessor didn't have enough drive strength and that reduced the output to just under 2v.
I do have another 3v regulator that's always active in order to keep the microprocessor powered while in sleep mode. I've done all I can to make sure the microprocessor is not holding any pins high that could potentially feed back through any parts powered by the TPS54308 or the LP5912.
Any suggestions would be greatly appreciated.
