nRF51822 observer power consumption profile

RE: nRF51822 observer power consumption profile

ToTo — Wed, 06 Apr 2016 10:32:07 GMT

I want to calculate the estimated current consumption referring to nordic documentation(the document you just shared) how?? .. In fact i can't pick how much time each stage ( A, B, C, ...) dures

RE: nRF51822 observer power consumption profile

sunil.dhaduk — Tue, 15 Sep 2015 11:55:49 GMT

Hi Stefan,

Thank you for your reply..

As observer will periodically enabled the receiver, it needs some amount of peak start up current and time as well as some pre-processing and post-processing before it goes to idle again like .

Is there any event current profile with different stage and description for observer mode?

It would be easy to calculate average current consumption from event current profile.

RE: nRF51822 observer power consumption profile

Stefan Birnir Sverrisson — Tue, 15 Sep 2015 09:23:45 GMT

Thanks for your question.

The current consumption profile of an observer is the most simple one. It is basically the current consumption of the Radio RX, which is 13mA with LDO. If you have nRF51 third revision and S110 8.0.0+ (further information on this thread), then the nRF51 uses the internal DC/DC, which will lower the current consumption of the Radio RX to perhaps 10mA - 11mA, see the DC/DC efficiency graph in figure 11 in nRF51822_PS v3.1.

Normally, the observer/scanner does not have the receiver enabled all the time. It is normally only periodically enabled. This is determined by the scan interval and scan window. If the scan interval is equal to the scan window, then the scan is continuous. If the scan window is half the scan interval, the average current consumption is also 50%, i.e. ~5mA - 6mA

Update 15.9.2015 The observer power profile plot is actually available in the latest S130 Softdevice specification.

An observer role device essentially just listens (scans) on the three advertising channels. If active scanning is used, the observer will send a scan request when it hears and advertiser, and will listen for a scan response. If passive scanning is used, the observer will simply listen for advertisement packets.