nRF52805-Power consumption decreases with the addition of a 10uF capacitor

[sunmnengnan]

HI  all,

  I've found that adding a 10uF capacitor to the 52805 beacon reduces the power consumption, especially after speeding up the broadcast interval (100ms broadcast interval).

 The conclusion is that the reason for the high power consumption without capacitors is the high total power consumption during broadcast (average current of one transmit wave peak * peak duration)

 btw, beacon with chip and peripherals only,the firmware is Nordic official routine, it can broadcast only, 100ms, 4dBm.

 We also tested the 52810 beacon and found the same phenomenon, but we don't have a more accurate power consumption test instrument, I'm not quite sure if it's the addition of this capacitor that reduces the power consumption, or if the power consumption board (PPK2) can't measure it.

Nordic 52805 beacon带不带10uF电容功耗对比测试.xlsx

[Menon]

Hello,

It looks like you're encountering issues with measurement accuracy over short time spans. These measurements are significantly influenced by spikes caused by switching between ranges. As mentioned in the ticket, the capacitor helps to smooth out these harsh transitions and reduce the fluctuations from the internal range switches of the PPK2.

Please keep in mind that our measurements have a +/-10% accuracy specification within this range. For most samples in your Excel sheet, the accuracy is within or just outside of this specification.

As Håkon noted, if you require this level of detailed accuracy, it is advisable to use another tool to verify your measurements and setup. An inaccuracy of around or slightly above 10% on spiky measurements is typical since the PPK2 is a development tool and not intended for certification purposes.

Additionally, please ensure you are using the latest version of the Power Profiler app (v4.2.0), as it includes updates that improve stability and accuracy in some scenarios. You can easily revert to your current version if needed.

I would also recommend checking the VDD line with an oscilloscope. If there are long lines, they might introduce noise, which could impact the current measurements.

Additionally, it would be helpful if you could provide a picture of your setup(if possible). Often, visual inspection can reveal issues that may be causing problems.

Kind Regards,

Abhijith

[sunmnengnan]

HI,

Understood, we tested it with the Power Profiler and found that the capacitance really has no effect on power consumption. I will update the Power Profiler app . Thank you for your answer!