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

[GLNeedham]

Simon,

I can confirm that I am NOT measuring between the wake-up/HFCLK start until the radio starts up but am in fact measuring between advertising so the 100uA does make sense in that context.

As we have SPI initialised but no CSN activity I suspect that block is consuming more or less nothing, the RTC also draws very little. The PWM block is initialised but not generating an output therefore should be consuming more or less nothing. The I2C is initialised and will likely consume typically 50uA

Also, because we have peripherals initialised then the internal HF OSC is likely running which consumes typ. 60uA

I assume the HF XTAL OSC only starts when the radio is needed (in our application)?

So, in theory we have ~50uA for the I2C plus ~60uA for the internal OSC giving a total of ~110uA which fits more or less perfectly with measurements

Your other comment about me misunderstanding the OPP was correct, I had assumed 'standby' meant between advertising, I had not fully taken notice of the ~1000us duration!!

Assuming my comments above are correct then I think we fully understand the situation now so many thanks for your help

Regards

Glenn