Some questions about nRF9160 power consumption

[Simon zhuo]

1.The last datasheet doesn’t show the GPS work current. Where can we get the data？

2.How long does the chip GPS finish one location action normally？

3.In datasheet chapter 5.2.1.14, it lists some modem current consumption. What’s the different between the IRMC_23DBM and ITX_23DBM ?

4.IRMC_23DBM is average current ? ITX_23DBM is continuous current? If we  want to calculate the battery capacity, which current can be used?

5.Where can we get the RX current consumption?

6.When the modem peak current appear? It just appear in startup stage or in whole modem work time?

7.Can you share some LTE-M  event detail like the nRF52840  BLE event detail？

[Simon zhuo]

Hi Bjorn

any update？thanks！

[Bjørn Kvaale]

Hi Simon,

3) The I_TX,23 DBM describes the modem active current consumption at an output power of 23 dBm. The I_RMC,23 DBM describes the radio resource control mode at the same output power of 23 dBm. As this link says, the RRC major functions are "connection establishment and release functions, broadcast of system information, radio bearer establishment, reconfiguration and release, RRC connection mobility procedures, paging notification and release and outer loop power control".

RMC may refer to a Reference Measurement Channels mode, which allows "stable, predictable behavior for radio testing". If you want to find out more, I would take a look at 3GPP TS 36.521-1 Annex A.2.

It could be that the RMC mode also varies between data transfer & sleeping, which could account for the lower current in I_RMC compared with I_TX.

4) I believe both are average current, only that the I_TX is the current when the modem is actively transmitting data.

I would take a look at the energy efficiency chapter here:

...

In my opinion, the best way to calculate battery capacity is to develop the application program, download the FW to the nRF91 DK & see the measuring current chapter in the nRF9160 DK User Guide v0.7 here.

5) It does not seem the RX current is listed in the OPS. I would see if you can measure it with an oscilloscope like described in Chapter 6 of the nRF9160 DK User Guide v0.7.

6) Let me double check this. I believe the same answer applies like I gave in answer 4 & 5.

Update: The peak modem current occurs when the nRF91 sends data (radio is in TX mode). There can naturally be variations in between sending packets. The current consumption may show a similar pattern to when the radio is in TX mode on the nRF52 (see link):

7) If it is not in the documentation available here (nRF9160 Core Documentation), then I am not sure this is available yet unfortunately.

Kind Regards,

Bjørn

[Simon zhuo]

got it.Thanks!

[Bjørn Kvaale]

I updated the answer to question 6.

[Simon zhuo]

Thanks.One more question, When will the GPS FW can be ready?

[Bjørn Kvaale]

I sent you a private message on devzone. Please take a look at the message.