nRF9160 Low Power

[danimalia]

Hi, 

We are battling to get to the advertised low power values as described here: 

https://devzone.nordicsemi.com/guides/cellular-iot-guides/b/hardware-design/posts/measuring-psm-idle-current-on-the-nrf91-dk

On our custom board, we average ~0.9mA with only the nRF9160 powered up, running the firmware linked in that post (7411.merged.hex)  and a 3.7V supply. 

We are running modem firmware 1.3.1. and testing using the PPK2 in source meter mode.

Our application firmware is based off of asset_tracker_v2 and running on ncs 1.5.1; we get similar results. prj.conf and schematics attached. 4087.Schematic Prints.PDF4555.prj.conf

Any help getting the sleep current down is appreciated. 

Kind regards

Dan

[JONATHAN LL]

Hi,

Where\how did you connect the PPK2 ? To CON1 in your schematic? 

Is anything else connected to the device ?

Kan you share the PPK2 measurement file ?

From the picture it looks like supply is 400mV in the PPK app. 

I dont see anything wrong in the schematic at first glance. Just make sure that only the nrf9160 is powered, seems to me that something else is drawing current. 

Have you followed guide to check base idle current, i.e measurement setup?
(+) Getting started with current measurements on the nRF9160 - Hardware design, RF test and coverage - Cellular IoT guides - Nordic DevZone (nordicsemi.com) 

 
Regards,
Jonathan

[danimalia]

Hi Jonathan 

Yes, connected to CON1. Here is my setup: 

PPK file attached. Supply voltage was set to 4000mV, not 400mV. 

Your suggested thread gave me the same results and the attached PPK file is with the hex shared there: 1452.sysoff.hex

I have desoldered the Telit and the LIS2DH ICs so unless the PMU is sucking current I don't see where else it's going.

FWIW - I ran this same hex on the DK in PMU mode and got around 60uA. 

Thanks
Dan 

edit: the PPK file is not uploading for some reason. Please email me and I will send it to you.

[JONATHAN LL]

Hi,

danimalia said:

edit: the PPK file is not uploading for some reason. Please email me and I will send it to you.

Put it in a zipped file, then you can upload it. 

danimalia said:

PPK file attached. Supply voltage was set to 4000mV, not 400mV. 

Yes, sorry for the confusion, typo on my side. 

danimalia said:

Your suggested thread gave me the same results

Thanks for clarifying that the measurement setup works as expected. 


The GPS LNA does draw som current but according to the datasheet it does not account for the difference in current draw you se, you could try to remove it and se if there is any notable change. 

Our current expert on nrf9160 power consumption is on vacation but will be back soon(next week). I am not 100% sure where the issue could be, but if you have a different unit you can test on that would be great, just want to confirm that it is not just that one device. 

Regards,
Jonathan

[danimalia]

Hi Jonathan 

PPK is attached. I also removed the LNA, did not make a difference. Will test on another unit as well. 

Thanks

Danppk-20220419T232752-data-logger.zip

[danimalia]

Hi Jonathan 

I tried on another unit with the same results (2 units in fact). 

Is your expert back yet? 

Thanks

Dan