NRF9160 current consumption continuous and peak during network discovery

[fh_nbt]

While developing the power supply for edge cases of NRF9160-SIBA we encountered problems with both the continuous and peak current consumption, mostly during startup. We are using a custom board.

Everything works under room temperature and fair network signal strength. However, when starting up the device and starting network discovery, we see a continuous current of [email protected] with peaks of up to 500mA/100ms. The peaks are difficult to capture as they always seem to be of different amplitude and duration. Obviously these values are difficult once a Li-SOCl2 cell is used at temperatures below zero degree celsius or past mid-charge.

Are there any options to reduce the total energy used for network discovery or increase discovery time in order to reduce average power?

Is there any documentation regarding peak current + corresponding peak duration?

[Stian Røed Hafskjold]

Hi, current consumption numbers are documented here: https://infocenter.nordicsemi.com/topic/ps_nrf9160/_tmp/alta.nRF9160/autodita/CURRENT/parameters.id_current_modem.html?cp=2_0_0_4_1_0_14

48mA is the modem in RX mode, which is necessary for network discovery, and the up to 500 mA peaks are the TX peaks. The duration is dictated by the network and the 3GPP spec. The TX output power is also decided by the network and cannot be set to a fixed level to reduce the peak current.

You can choose to turn off the modem if the network discovery takes too long, and try again later. But this would be in the "tens of seconds" time scale, and probably won't solve your specific issue.

[Stian Røed Hafskjold]

I also want to add that the numbers in the link I posted are from the revision 2 of the nRF91. The peak currents have been improved on rev. 2. Here is the old product spec for rev 1: https://infocenter.nordicsemi.com/pdf/nRF9160_PS_v1.2.pdf

Please check the build code on the SIP and make sure you are measuring on rev 2 (B1). Here's a list of SIP revisions: https://infocenter.nordicsemi.com/topic/comp_matrix_nrf9160/COMP/nrf9160/nrf9160_ic_revision_overview.html?cp=2_0_3_0