3 Replies Latest reply on May 13, 2014 12:49 PM by legic_1490776

    System sometimes draws 3mA after entering HIDOFF mode

    legic_1490776

      I have a custom board design based on the 20732S, which has a button that allows the system to wake up from HIDOFF mode if the button is held down for more than 3 seconds.

       

      My application enters HIDOFF mode and I see a very low power draw (~2 microamps).

      When I press the button briefly, the system wakes up, waits about a second, sees that the button is not pressed anymore, prints a BLE trace message, and re-enters HIDOFF mode.

       

      About half the time, the device enters HIDOFF and the current goes down to 2uA again.

      The other half of the time, the device still appears to enter HIDOFF mode (it stops operating) but the current draw rises to 3 MILLIamps and stays there permanently.  If I press the button again to wake it up, it wakes up just as normal (a normal boot from HIDOFF) and operates as expected.

       

      What could cause this behavior, and is there anything I can do to prevent it? 

      Could this be caused by some interrupt input occurring at a bad time when trying to go to sleep?