5V power measurement PCA10040

[Hugo]

I need to measure full power consumption of nrf52, on PCA10040 from... a 5V source (because including some other 5V devices).
I measure it from 5V pin and not usb plug.
I cut SB29, to remove atmel processor leak. But I stil get around 4.5mA leakage (all led off), I don't know where from, and it seems huge for a regulator. (around 5mA +peaks while advertising)
Shoud I cut some other lines to only keep the regulator and nrf52 powered?

[Simonr]

Hi

What measurement tool(s) are you using to measure the current on the DK? Have you checked out chapter 6.7 in the DK User guide which tells you how to measure the current consumption of either the whole board or the onboard chip? First of all, you should cut SB9, as P22 should be used to measure current consumption on the DK.

You can also check out the Power Profiler Kit which is made specifically for measuring current consumption on our nRF5 series and comes with a very thorough user guide and its own application in nRFConnect for Desktop.

Best regards,

Simon

[Hugo]

I read already all these documents, but thank you for the advice.
I'm using Agilent 66309D+GPIB as a cheap but efficient SMU, but neither a scope, nor on ampermeter.
Also, I need to measure power from 5v to be able to include external devices, and the full system estimation connected to 150mA device which is out of your board scope, but compliant with my SMU.

I still have the same problem: how to power efficiently the board through 5V, without current leak?

[Simonr]

Hi Hugo

Keep in mind that you can't supply the nRF52832 directly with 5V, as the maximum voltage rating is at 3.9V. Can you upload a picture or schematic of your test setup so I can get a clearer image? The DK/nRF is not connected to any peripherals what so ever, correct? Also, what application are you running on the nRF, is it one of our example projects or some custom code?

Best regards,

Simon

[Hugo]

thanks. This is a new test from nordic uart exemple sdk15.3, 1st graph: advertising, 2nd graph: connected, sb29 cut, powered through 5V.
I think it's still far higher than what I should expect, it's nearly close to an Arduino x) . On the board shematics, there is a 300ma 3.3V AP7333-33SAG-7 regulator that shouldn't use so much current. So I'm missing something, but what?

ps: the power seems quite noisy, I don't know why, but I checked with a resistor and it's still well calibrated, no offset. It's missing some peak, as read frequency is 2ksample pr second,  which doen't seems enough to see everything.

[Simonr]

Hi Hugo

Indeed, these graphs look very noisy indeed. I assume the Y-axis' value is in Amperes, and if so it definitely looks very high. What application code are you running on the DK, is it one of our example projects or your own custom code? Here on my side, I have the following graph for the DK advertising regularly (ble_app_blinky).

Best regards,

Simon