Emergency!! nRF52840 Re-boot when I plug the AC power

[Gordon Liu]

Dear Sir,

I use the nRf52840 DK (PCA10056) which be a ICE to download FW and 3V DC power supply for my DUT.

the 3Vdc connect to Vdd.

I use the DK 3Vdc be my power supply and the DK use the NB USB 5Vdc.

I can load FW and it's running OK.

I find out my DUT is running OK when the NB only use battery.

And then I plug the NB AC Power, my DUT re-boot.

Do you know what happen??

[Håkon Alseth]

Hi,

 

I find out my DUT is running OK when the NB only use battery.

And then I plug the NB AC Power, my DUT re-boot.

Have you scoped the VDD_NRF line to see if there's any spikes on that line?

 

Kind regards,

Håkon

[Gordon Liu]

I only connect the GND of Scope so that my DUT re-boot.

[Håkon Alseth]

Gordon Liu said:

I only connect the GND of Scope so that my DUT re-boot.

I understand. Still, the issue needs to be measured and isolated. You should measure and see if there is a spike or similar on the VDD_NRF line. Try another scope, or keep it connected to GND/VDD; then reproduce the issue.

 

Kind regards,

Håkon