excessive current draw in QN908x via EXTI

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excessive current draw in QN908x via EXTI

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arpad_toth
Contributor II

Hello,


I get excessive current draw on QN9080DK devboard when using EXTI + PD0 mode:

  • SW: Based on "power mode switch" demo app (forced to always return PD0 mode).
  • Setup HW PA19 as input.
  • Setup HW to wakeup on Button2 (PA19) low level.
  • Go to PowerDownMode0.

In PowerDownMode0 it consumes 4uA which is fine.

But when I press and hold Button2 it consumes 870uA!
Which is super high, also SW already gone back to PD0 state.

After releasing the button it goes back to 4uA.

Pressing the other Button causes ~1uA change.

  • So firmware is not running, it's in PD0.
  • Button2 is not connected to anything else HW wise.
  • Thus 870uA must come from MCU internal hardware.

Disabling wake up source after the wakeup didn't reduce the current:
   SYSCON->PIO_WAKEUP_LVL0 = 0;
   SYSCON->PIO_WAKEUP_EN0 = 0;

Is it a silicone bug? How can we mitigate it?

Thanks,

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estephania_mart
NXP TechSupport
NXP TechSupport

Hello, 

Are you sure you are following the correct procedure to wake the device with the GPIO? As well as not using the same pin for another type of functionality? 

If the firmware it's not running you might have some kind of fault if not properly configured or if the process was not followed correctly. 

Regards, 
Estephania 

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arpad_toth
Contributor II

Hello,

Please see the attached project.

It was minimally modified compared to the original example. Forced to always go to PD0.

No pin functions were modified.

If you download to QN9080 DK devkit.

  • Remove JP15
  • Press reset
  • Goes to PD0
  • Press+hold SW2 -> current increases during button press
  • Current measured in place of JP14 with scope
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estephania_mart
NXP TechSupport
NXP TechSupport

Hello, 

There are some missing files that do not let me see completely how are some things being enabled. 

By any chance, have you checked the process on the Heart Rate sensor? The board wakes up when pressing one of the buttons and it should work and be a better guide for you. 

Regards, 
Estephania  

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