Current consumption of the modem inside nRF9160

RE: Current consumption of the modem inside nRF9160

Martin Lesund — Wed, 26 Aug 2020 14:51:29 GMT

RSSI is not detectable, RAT not supported. Use +CESQ and %CESQ for E-UTRA signal quality.

RE: Current consumption of the modem inside nRF9160

WassimZ98 — Fri, 21 Aug 2020 15:55:00 GMT

OK I will try. I have another question regarding RSSI. Can i know directly the RSSI value? The AT commad CESQ only gives me RSRP and RSRQ.

RE: Current consumption of the modem inside nRF9160

Martin Lesund — Fri, 21 Aug 2020 09:41:32 GMT

There is something incorrect with your test setup when measuring the SLM sample.
Please make sure you have prepared your DK nRF9160 0.8.2 version correctly for measurements and also use another measuring equipment to have something to compare with.

RE: Current consumption of the modem inside nRF9160

WassimZ98 — Thu, 20 Aug 2020 22:05:05 GMT

Almost same thing, but this time the current oscillates between 0.6uA to 1.3uA.

RE: Current consumption of the modem inside nRF9160

Martin Lesund — Tue, 18 Aug 2020 11:23:36 GMT

Hi Wassim,
Could you please redo the test while the nRF ONLY switch is to the left and VDD_IO is 3V ?

Since there is a bug on that DK version you should have these configurations.

RE: Current consumption of the modem inside nRF9160

WassimZ98 — Mon, 17 Aug 2020 17:26:35 GMT

I have tested the Serial LTE modem firmware, but i see a strange behaviour.

I am supplying power from the USB port J4. The switch nRF ONLY is on. I am measuring current with a multimeter. When the VDD_IO switch is set to 1.8V, the current is about 5uA (modem is PSM and I isued the AT#XSLEEP=0 command). But when the VDD_IO switch is on 3V the current is insignificant, about 0.2uA. Is it normal?

RE: Current consumption of the modem inside nRF9160

Martin Lesund — Mon, 17 Aug 2020 06:27:13 GMT

If using an Oscilloscope, that is the recommended approach according to the documentation..
If using a power analyzer or a current meter that is not needed.

RE: Current consumption of the modem inside nRF9160

WassimZ98 — Sun, 16 Aug 2020 13:23:13 GMT

Thank you very much for the answer. I haven't tested it yet, but i have another question. Do i have to solder an 0.5 ohm resistor on R60?

RE: Current consumption of the modem inside nRF9160

Martin Lesund — Fri, 14 Aug 2020 08:14:22 GMT

Hi Wassim,
I assume you are running the Serial LTE Modem on the nRF9160.

To turn OFF the UART you can run the command "AT#XSLEEP=0".

Unfortunately there is a bug in the Zephyr implementation of the UART that affect this sample to leak 23µA. So in PSM mode you should see around 27µA.

(There is ongoing work to fix this, and hopefully it will be introduced in the master branch in the near future)

To see the numbers in the datasheet I would instead invite you to run another sample. e.g. modify the coap_client sample or just run this simple udp_psm sample

Change the hostname out with e.g. the static IP address to your UDP server. Then you should see the 4µA in PSM mode.

I see that you have the v0.8.2 DK, which has a ~2µA leakage issue if the VDD_IO switch is set to 1v8, so it is recommended to have the VDD_IO switch (it is right next to the power switch) set to 3V when doing power measurements.

Here you can see the PSM floor current when running the udp_psm sample:

Best regards,
Martin L.