How to turn external regulator off and run in low power mode (backup domain) ?

gregor · ‎2010-03-11

Posted on March 11, 2010 at 20:17

bfredr · ‎2011-05-17

Posted on May 17, 2011 at 13:43

Hi Berke,

A wild guess.

When you switch off the external regulator, the supply voltage slowly drops (as you have large bypass capacitors on the supply line). At a certain voltage (1.8V or so) the MCU detects low voltage and makes a reset as it's supposed to do. If you now have enough supply voltage after the short reset, the MCU will reboot.

Try connecting an oscilloscope to see if I'm wrong.

Bo