Hi,
Please see below a typical current consumption at 25°C:

You can find a detailed description of stop modes in the device datasheet.
In the project, the LF block is enabled in STOP1 in case the mode LF_COMMUNICATION is selected.

The selection of the mode is to be done in the file user_configuration.h of the project.
In this file, there is the possibility to select three different modes, one using LF (LF_COMMUNICATION) and two not using LF.
I would recommend to select the mode NO_LF_PWU: with this mode the FXTH wakes up periodically to send RF frames, and between two transmissions it goes to STOP1 with LF disabled. With this mode you should see a power consumption of 500nA between two RF transmissions.
Best regards,
Tomas
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