External supply power consumption is different from current consumption measurement using PPK2

RE: External supply power consumption is different from current consumption measurement using PPK2

Ashishsult — Tue, 16 Aug 2022 06:41:27 GMT

We built our in-house customized board and to measure the power consumption of whole module, I power it from the Nordic PPK2 directly supplying 3.6 V to the our module.

RE: External supply power consumption is different from current consumption measurement using PPK2

Tai — Mon, 15 Aug 2022 22:46:56 GMT

Hi Ashishult,

Did you use Source meter or Ampere meter method to measure current consumption in your customized board? I'm using the Source meter method, but I got very high current consumption (a few mA).

RE: External supply power consumption is different from current consumption measurement using PPK2

Ashishsult — Tue, 24 Aug 2021 09:58:15 GMT

Thanks a lot, Hakon,

I tried with a customized board and I receive lower power consumption.

It is better if nrf9160DK had provided the lower consumption via external battery, but I can understand its early phase DK.

RE: External supply power consumption is different from current consumption measurement using PPK2

Håkon Alseth — Tue, 10 Aug 2021 11:59:55 GMT

Hi,

[quote user="Ashishsult"]But with the current status of the application and hardware, I can't because the power consumption came out to be 8.96 mA in RRC idle state. [/quote]

As shown in the DK schematics and layout, P21 will power the whole board.

This is a development kit restriction, and will not apply when you create your custom board.

As I mentioned, if you power it as I showed, the leakage will be lower (but it will still leak through switches etc.)

Here is the description on how to measure the nRF9160 isolated:

https://infocenter.nordicsemi.com/topic/ug_nrf91_dk/UG/nrf91_DK/hw_measure_current.html?cp=2_0_5_5

It also states:

The use of a USB connector is not recommended for powering the Development Kit (DK) 
during current measurements due to potential noise from the USB power supply. 
Instead, the DK should be powered by connecting a power supply to connector P21.

Kind regards,

Håkon

RE: External supply power consumption is different from current consumption measurement using PPK2

Ashishsult — Tue, 10 Aug 2021 11:50:24 GMT

I understand that buttons, LEDs, Pins consume power. I worked a bit with nrf52840 Dk board where we can not initialize them and then the power consumption can reduce. Is it possible with nrf91 DK to do so?

For me, this is important because I want to power the device with an external battery and keep the device in PSM mode for a long time to save energy. But with the current status of the application and hardware, I can't because the power consumption came out to be 8.96 mA in RRC idle state. I can tolerate few micro-amperes leakage currents but from uA to mA is too much.

RE: External supply power consumption is different from current consumption measurement using PPK2

Håkon Alseth — Tue, 10 Aug 2021 11:08:36 GMT

Hi,

If you measure on P21, you are powering more than just the nRF9160 (switches +++). If you follow the "VSUPPLY" (which is the net P21 powers), you can see this clearly from the schematic/layout:

https://www.nordicsemi.com/-/media/Software-and-other-downloads/Dev-Kits/nRF9160-DK/Hardware-files/nRF9160-DK---Hardware-files-1_0_0.zip

Since features like LEDs etc are buffered, and there are connected lines between the debugger and the nRF9160 on the DK itself, you will have some leakage when powering only the nRF9160.

To measure the nRF9160 isolated, you can power it as shown in my former post (w/o usb connector present, you will get a lower consumption if USB is on). This will still have some leakage, but not in the high mA range:

Kind regards,

Håkon

RE: External supply power consumption is different from current consumption measurement using PPK2

Ashishsult — Mon, 09 Aug 2021 13:44:39 GMT

Yes, for the source meter mode, as I told you with this connection and also with the ampere mode, the device can now go to the PSM mode consuming only around 8 uA (my second attempt).

But if I connect Vout and GND (PPK2) to the P21 (nrf91 DK), the current consumption is in mA. This is my main concern because I want to power the device with a battery and want to increase its life using the PSM feature of NB-IoT.
As current consumption having USB connected shown numbers in uA which is good to know but in practice, if I can also achieve that then it's useful for me.

RE: External supply power consumption is different from current consumption measurement using PPK2

Håkon Alseth — Mon, 09 Aug 2021 13:38:29 GMT

Hi,

[quote user="Ashishsult"]But power consumption from the external supply pins P21, is still in mA. Do you have an idea if I need to somehow disable the peripherals to reduce the power consumption or there is any other solution?[/quote]

Are you connecting as described here?

Ie. the GND pin from P21, then the "VOUT" to the VDD_NRF:

Kind regards,

Håkon

RE: External supply power consumption is different from current consumption measurement using PPK2

Ashishsult — Mon, 09 Aug 2021 13:30:49 GMT

I did the setup as mentioned here: https://infocenter.nordicsemi.com/pdf/PPK2_User_Guide_v1.0.1.pdf

I re-attempted the test now the source and ampere mode have a similar result.

But power consumption from the external supply pins P21, is still in mA. Do you have an idea if I need to somehow disable the peripherals to reduce the power consumption or there is any other solution?

RE: External supply power consumption is different from current consumption measurement using PPK2

Håkon Alseth — Mon, 09 Aug 2021 13:16:19 GMT

Hi,

How are you connecting the PPK2 to the nRF9160 when its in "source meter"?

Kind regards,

Håkon