nRF9160 Low Power

RE: nRF9160 Low Power

danimalia — Tue, 26 Apr 2022 21:45:13 GMT

Hi Jonathan

Thanks for the detailed response - I'll reply in detail again tomorrow; but I think the PMIC may be the culprit as you've suggested.

Thanks

Dan

RE: nRF9160 Low Power

JONATHAN LL — Tue, 26 Apr 2022 13:36:38 GMT

Hi Dan,

[quote user="danimalia"]I tried on another unit with the same results (2 units in fact). [/quote]

Great to know.

[quote user="danimalia"] I also removed the LNA, did not make a difference.[/quote]

Thanks for checking.

[quote user="danimalia"]PPK is attached[/quote]

Thanks.

The unusual high current draw does seem to point to that something else is powered in addition to the nrf9160, all other IC's of relevance should have been removed.

In you .conf file you do have logging enabled, and SERIAL is not explicitly disabled, have you seen the overlay-low-power.conf in the asset tracker example?

Could you test your application with the following in .conf

# Disable serial interface.
CONFIG_SERIAL=n

# Disable LEDs
CONFIG_LED_CONTROL=n

# Disable UART console.
CONFIG_UART_CONSOLE=n

# Disable event logging.
CONFIG_APP_EVENT_MANAGER_SHOW_EVENTS=n

# Disable AT host library.
CONFIG_AT_HOST_LIBRARY=n

# Disable logging
CONFIG_LOG=n

But if you where testing with the hex file from the blog post then this should not be the issue.

Update:

Can you confirm that when you followed the process of "Checking your measurement setup" that you get the same value as in the blog post?

You say: Your suggested thread gave me the same results and the attached PPK file is with the hex shared there: 1452.sysoff.hex
Do you mean that you get 0.9mA, as you show in the PPK2 file?

You should see something that matches the sleep specs, so les then 2uA.
https://infocenter.nordicsemi.com/topic/ps_nrf9160/_tmp/alta.nRF9160/autodita/CURRENT/parameters.id_current_sleep.html?cp=2_0_0_4_5_0_1

It is very important that you are able to verify the setup.

Update 2:
The PMIC might be the culprit here. The mode pin in your design is pulled low to ground, this sets the PMIC in Constant-Frequency (PWM) Mode operation. From the data sheet:

In this mode, it uses a current mode architecture including
an oscillator, an error amplifier, and a PWM comparator
for excellent line and load regulation. The main switch
MP2 (P-channel MOSFET) turns on to charge the inductor
at the beginning of each clock cycle if the FB pin voltage
is less than the 0.8V reference voltage. The current into
the inductor (and the load) increases until it reaches the
peak current demanded by the error amp. At this point,
the main switch turns off and the synchronous switch
MN1 (N-channel MOSFET) turns on allowing the inductor
current to flow from ground to the load until either the
next clock cycle begins or the current reduces to the zero
current (IZERO) level.

Pulling the Mode pin high will put it in Burst Mode, this should reduce the current consumption.

You can tie the pin to one of the nRF9160 GPIO's and switch between BM and CF.

Might need to bypass the PMIC to get the same results as in the blog post, and confirm that it is the PMIC that is causing the unexpected current draw.

Regards,
Jonathan

RE: nRF9160 Low Power

danimalia — Mon, 25 Apr 2022 20:55:58 GMT

Hi Jonathan

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

Is your expert back yet?

Thanks

Dan

RE: nRF9160 Low Power

danimalia — Thu, 21 Apr 2022 20:04:23 GMT

Hi Jonathan

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

Thanks

Dandevzone.nordicsemi.com/.../ppk_2D00_20220419T232752_2D00_data_2D00_logger.zip

RE: nRF9160 Low Power

JONATHAN LL — Thu, 21 Apr 2022 14:30:01 GMT

Hi,

[quote user="danimalia"]edit: the PPK file is not uploading for some reason. Please email me and I will send it to you.[/quote]

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

[quote user="danimalia"]PPK file attached. Supply voltage was set to 4000mV, not 400mV. [/quote]

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

[quote user="danimalia"]Your suggested thread gave me the same results[/quote]

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

RE: nRF9160 Low Power

danimalia — Tue, 19 Apr 2022 23:36:25 GMT

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.

RE: nRF9160 Low Power

JONATHAN LL — Tue, 19 Apr 2022 13:18:01 GMT

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