Is there any problem in current consumption of nRF52-DK when SB9 is not opened ?

[Daewoong Kim]

Hi Experts!

I read some posts related to current measurement, and i have a question.

if SB9 is not opened, current consumption is increased??

i have a Source Measurement Unit (SMU), manufactured by (NI)National Instruments (NI PXIe-4139, NI PXIe-1078),

so i measured current consumption by applying power to Extneral supply port (P21) on nRF52-DK.

However, the measured idle current is about 160~170uA between advertising events.

Of course i used "sd_power_dcdc_mode_set(NRF_POWER_DCDC_ENABLE)" and "sd_app_evt_wait()" functions.

Also, I disabled NRF_LOG_ENABLED, NRF_LOG_BACKEND_SERIAL_USES_UART, and just advertising operation

conducted without any other operation.

Anyway...

At least, i want to know about whether the cause of idle current of 160~170uA  is SB9 shorted or not ..!

please answer..!

- Daewoong Kim

[wlgrd]

No, it doesn't matter. 
SB9 is cut when you want to measure current over P22, using a scope over R6 or an amperemeter (or the Power Profiler Kit). 

I would advise to solder SB12 to bypass the protection diode D7 when using the SMU at P21 though. Just remember that the external supply is not protected against reverse voltage when a USB is used for powering the DK then. 

[Daewoong Kim]

Thank you for your reply!