nRF51422 Current Consumption

[Dilip]

Hi,

We are currently working on nrf51422 bluetooth IC. we are facing a problem with the ic when we want to put it in sleep mode. without sdk when we call WFE() function it is going to sleep mode and taking 25uA but when we flash softdevice and call sd_power_system_off it is not going to sleep mode infact it is taking more current than usual.

Give me solutions to overcome this problem

[endnode]

Note that sd_power_system_off is something completely different then SYSTEM ON SLEEP mode which you normally achieve by running WFE/WFI instructions. This is trying to send SoC to POWER OFF mode which is deeper sleep. However because you most probably don't turn all necessary interfaces down the chip don't get to that state so power consumption which you observe is standard operation curve (SYSTEM ON state if you want). To send nRF5x SoC to SYSTEM ON SLEEP mode through Soft Device API you should use sd_app_evt_wait function call.

[endnode]

Have you seen blog posts how Nordic analyze power consumption with Power Profiler Kit? Something like that. You can then clearly see what is baseline and what are periodic peaks of activity (and from their values you can assume what is in use). Also once you migrate from example app which runs on bare metal/HAL to app which uses SoftDevice you can do quite a lot during Soft Device initialization. So by seeing this sequence of the code we could understand what can be running.