4 Replies Latest reply on Aug 9, 2018 2:54 AM by gani

    PSOC3 (CY8C3865) sleep current too high (~28µA) - What could be the cause?

    user_439324545

      Hi,

       

      I have a design based on a CY8C3865LTI-014.

      I noticed that in reality the sleep current was much too high than anticipated (more than 25µA higher).

       

      The steps I took to debug this were:

      - remove all components but the PSOC and the surrounding caps from the PCB

      - build a fresh project without components, and only this code:

       

      ```

      int main(void)

      {

          CyGlobalIntEnable; /* Enable global interrupts. */

         

          // set 32kHz crystal to operate in low power mode when in sleep

          CyXTAL_32KHZ_SetPowerMode(1);

         

          //start WDT

          CyWdtStart(CYWDT_1024_TICKS,CYWDT_LPMODE_DISABLED);

         

          /* Place your initialization/startup code here (e.g. MyInst_Start()) */

          CyPmSaveClocks();

          for(;;)

          {

              /* Place your application code here. */

              // clear wdt

              CyWdtClear();

             

              // sleep 1 s

             

              CyPmSleep(PM_SLEEP_TIME_ONE_PPS,PM_SLEEP_SRC_NONE);

              CyPmReadStatus(CY_PM_ONEPPS_INT);

             

          }

          CyPmRestoreClocks();

      }

      ```

      As one can see, after initialisation, the PSOC goes in sleep mode forever.

      When measuring the current, I still measure ~28µA, which is much more than the specified 1µA in the datasheet.

       

      What could be the cause of this high sleep current?

       

      I attached the project for you reference.