nRF52840 Low Power Mode Current Consumption

[NordicEmb20]

Hi,

  Using the RTC example in the 'nRF5 SDK 16 / examples / peripheral' as a starting point, we've programmed the rtc_handler to execute at regular intervals approx. every 1 millisecond. With an empty rtc_handler, the average current consumption is about 80 microamperes. 

  We are running the example and measuring the current on a nRF52840 Development Kit. The NRF_LOG_ENABLED is set to zero. The consumption when the RTC is disabled is 2.7 microamperes, as expected, but we are unable to reduce the consumption when the RTC is enabled and the rtc_handler interrupts execute.

  What would be the way to reduce the current consumption caused by the interrupts further? 

Thank you.

[Kenneth]

Hi,

If you wakeup every 1ms, then even with a empty callback handler the system would still need to wakeup, run the exception handler, call the callback, calculate the next wakeup, return to main and go to sleep. If we presume this take 20us and require 4mA; 4mA *0.020/1 = 80uA on average. To reduce the most efficient would be to wakeup more rarely.

Best regards,
Kenneth

[NordicEmb20]

Thank you for your answer, Kenneth!