RE: How to detemine SIMs contribution to current drain in 9160 design

Achim Kraus — Mon, 26 Jun 2023 10:10:44 GMT

I guess, you need to have a model/idea about that usage of the SIM.

Not only the current is relevant, also the state and the assumed times, your device is in that state.

In my experience:

- modem is RRC active, the current of the SIM is only the very minor part

- modem is RRC idle and using eDRX, then current of the SIM may dominate that phase (e.g. 10µA without considering the SIM, 25µA with the SIM). It also depends on the SIM and the eDRX period, if the SIM is switch off in eDRX or kept in that "stand by".

- modem in PSM sleep. AFAIK, the SIM is switched off and so you only have the quiescent current of the rest of your device.

The nRF9160-DK offers by the way a plug to measure the current for the SIM.

RE: How to detemine SIMs contribution to current drain in 9160 design

Sigurd — Fri, 23 Jun 2023 11:30:12 GMT

Hi,

See the "Sim card current consumption" chapter in this guide(last chapter in the guide): Getting started with current measurements on the nRF9160

PS: the OOP have this setting for SIM cards: