We are simulating a SIM-card. And the question is, do we need to level-shift the 3.3V from our CPU to 3.0V as the SIM-card specifications says, or do the Quectel modem handle the 3.3V? On the current hardware we have a voltage level shifter, but we have noise problems with that, so we would like to eliminate the voltage level shifter, if the modem handles 3.3V on the data signal from the SIM.
We are currently using Quectel EC25-E, and in the future we will use EM120R-GL.
Thanks for you query in Quectel forums.
The SIM card and module SIM pin voltage need to match, the module supports 1.8 or 3.0 V SIM card voltage, it is suggested to match the voltage to 3V or 1.8V according to the SIM pin voltage description in our module hardware manual, thank you.