VDD_TCXO not used at STM2WLE5JCI6

[Adielfr]

Hi,

We are using the STM32WLE5JCI6.

In our design, the TCXO (HSE) is powered directly by the 3.3 V on-board power supply, and the VDD_TCXO pin is left unconnected.

Is this acceptable?

Should we avoid using the Set_TcxoMode command in this case?

Thanks for any help

[STTwo-32 · Accepted solution]

Hello @Adielfr 

Yes, you can use an external power supply and not the VDD_TCXO pin. This approach is valid as long as the external power supply meets the TCXO's voltage and current requirements. The VDD_TCXO pin is specifically designed to provide power to the TCXO, but it is not mandatory to use it if an external power source is available and suitable. 

For the Set_TcxoMode command, you should not use it in such configuration.

Best Regards.

STTwo-32