NRF52DK power consumption with demo UART

[Maxim]

Hi, I am currently working to measure power consumption on a custom board and I found huge power consumption while advertising (BMD-300 1.15mA DCDC enabled).

So I have tried to do the measurement on my NRF52DK to see if there is any difference with the following procedure:

• Cut the SB9 trace
• bypass the diode with a short circuit on SB12
• Power the board with the provided coin cell

The full procedure is described Here

The program loaded on the NRF52 is ble_app_uart_pca10040_s132.hex directly provided by the nRF5_SDK_12.1.0_0d23e2a.zip. The program is loaded with nRFgo Studio.

And I measure:

1. -On advertise + Led1 blink: 2.85mA/3.05mA
2. -Connected + Led1 ON: 2.29mA
3. On sleep + Led1 OFF: 2.20µA

So my question is this normal to have so much power consumption on the NRF52DK or is my measurement are biased by my multimeter (Metrix Mtx 3281)

Thanks you for your answers !

[Maxim]

I have already read these figures, but i think my problem is the prescision of my measurements. I think my problem is my multimeter or my calculations, i'have found this interresting tutorial: Calculating average current from Oscilloscope and Ampere meter measurements avaible Here.

The average current on adv mode seems to be the same i have measure by myself (2.48mA/2.85mA), so the real consumption is much lower according to these calculations (~13µA).

So do you think this issue is due to the low frequency sampling of my multimeter or my method of measurement.