Idling with low-speed timer

[cth]

Hi,

I am trying to build a low power device using the nRF51422 SoC without a Soft Device. I need a timer to occasionally wake up the chip and as I read the product specification it should be possible to achieve a current consumption of 250uA when using only the 1MHz low-speed timer and a 16MHz crystal oscillator (PS 3.1, table 22, page 40). However, with an example from SDK 8.0 as starting point and the nRF51 development kit, I have not been able to get the power lower than approximately 550uA. I use the current measurement guideline from the DK user guide. What can be done to lower the current further?

A sub question: When programming using IAR the current consumption is considerable higher until the development kit is restarted. Is it possible to avoid this?

Best Regards, cth

[Susheel Nuguru]

Which SDK example did you use for this timer functionality?

answer to sub question) It is possible that IAR leaves the chip in debug mode after flashing which consumes more power. I do not have IAR setup now, so I cannot confirm this.

[cth]

Sorry, my bad. I didn't disable GPIOTE and it make use of additional current consuming parts of the chip. When using the timer alone my consumption dropped to approximately 270uA. I am not sure of my measurement accuracy, so I am satisfied. Thanks for your help!