Confusion with online power profiler.

[GLNeedham]

Hi, We are developing a product based on the nRF52832 and have been measuring the current consumption on our first prototypes with a Keysight N6705 power analyser. We seem to have a base current, when the CPU is sleeping of around 100uA which was higher than we expected.

By way of confirmation I used the Online Power profiler to get an idea of what to expect and it suggests a standby current of 200uA might be expected

This seems really high to me?

Also if I select the option to turn the DCDC on the standby current increases - also very unexpected?

Can anyone explain why the current profiler indicates such a high standby current? I would have expected it to be in the single digit microamps!!

By way of additional information our FW has UART logging turned off, the App uses the RTC to wake up every 100ms or so to do some work and we are running the LFOSC from a 32KHz Xtal.

May be I am missing something?

Many thanks

[Simonr]

Hi Glenn

I just ran the ble_app_template project on my side (on an nRF52840DK, didn't have an nRF52832 at hand), and measured the current consumption for some scenarios using the PPK and the Power Profiler application in nRFConnect for Desktop.

Average current while advertising (~140µA):

Average current in IDLE mode between advertising events (~24µA):

I think you're misunderstanding the Online Power Profiler, as the standby you're pointing to is what is between the wake-up/HFCLK start until the radio starts up, which is why it is stated as 0.2mA in the OPP. Can you confirm whether this is the timeslot you're measuring the current consumption in as well (see picture below), or are you measuring between the advertising events themselves?

If you're seeing 100µA in the idle between ramp-up and radio, there must be something wrong with the way you're measuring the current consumption, as the HFCLK is definitely running in this timeslot. If you're seeing 100µA between advertising events, that likely means that one of the peripherals you're using is not uninitialized properly.

Best regards,

Simon