Power profile pattern on nRF9160 with flash memory erased

[MuhammadTharwat]

Hello all, 

We 're working on our custom PCB prototype. 
We can see current consumption according to this profile even though the flash memory was erased. 
Also the modem FW has been upgraded to 1.3.0. We 're wondering what this pattern is ? and whether the chip consumes any amount of current for Radio 
in case flash is erased ? 
We know that the radio has it's own processor , but that should not be running anything before receiving a request from the M33. 
This pattern looks like the radio is searching or trying to register. 
Can you advice please? 
 

[JONATHAN LL]

Hi,

Can you share how you have connected the device to measure the power consumption?

 Try to follow the guide here and make sure that your setup produces the same result in system off mode so that we know that the results are dependable 
https://devzone.nordicsemi.com/guides/cellular-iot-guides/b/hardware-design/posts/getting-started-with-current-measurements-on-the-nrf9160 

So follow the "Checking your measurement setup" section and update me on the results and we will take it from there

Regards,
Jonathan

[MuhammadTharwat]

Hello Jonathan, 

Thanks for your reply. 
I have used that executable (System off) and I can see that the current pattern is the same. 
It's pretty strange the nRF9160 IC is not even warming up while the 3.3v regulator is going crazily hot. That suggests that the nRF has been assembled correctly. It is normal for the IC not to warm up in any modes of operation ? 
Our version is SICA B1. 

[JONATHAN LL]

MuhammadTharwat said:

I have used that executable (System off) and I can see that the current pattern is the same. 

Just to double down so that we are on the same page. You are saying that when you used the (system of) file  you got the same results as in the guide. Around 3 uA in system off mode?

MuhammadTharwat said:

It is normal for the IC not to warm up in any modes of operation ? 

The nrf9160 IC does not relay go hot unless you have a high average current for a longer period. So if you are not doning something that pulls a lot of power then it does not heat up that much. 



Do you have a SIM card connected to the device?

Regards,
Jonathan