3 Replies Latest reply on Mar 9, 2017 9:31 AM by fkoran_2092441

    Current slowly creeps upward after entering low power mode

    fkoran_2092441

      Hi, I'm running into some trouble with power consumption and I'm wondering if this seems like a design problem. Here's the situation:

         

      I have a dozen copies of a custom PCBA from a well established assembly house

         

      I have an empty project with a single pin assigned to 12.6, and the following code:

         

          pin_SetDriveMode(pin_DM_DIG_HIZ);
          CyDelay(10);
          CyPmSaveClocks();
          CyPmHibernate();

         

      I expect this design to draw around a microamp in sleep, but two instances of the board fail to do that. They start out drawing 0.4 mA and slowly creep up over a period of about a minute until they're drawing 4 mA. Toggling the reset line resets the cycle. All the other boards draw less than a uA.

         

      I discovered that if I set the drive mode to ALG_HIZ, these boards fall into line (although I do need PICU interrupts on this particular pin). There's a 200 kOhm pulldown on 12.6, and shorting the pin to ground or VDDD doesn't have any effect.

         

      Any ideas what could be causing this? DFM things to check? Thanks in advance!