Clarification on Clock Source Selection for STM32U575CGU3 in CAN J1939 & CANopen Application

[sasmitjoshi5]

I am currently working on a project that uses the STM32U575CGU3 microcontroller. The goal of the project is to display pressure and temperature values over CAN J1939 and CANopen communication protocols in a digital output format.

For sensor data acquisition, I am using an external two-channel ADC to measure pressure and temperature values.

Regarding the system clock, I have tested the application using both the internal clock source and an external crystal oscillator. The system performs well in both configurations.

However, I would like to request your expert guidance on the recommended clock source for this application. Specifically:

• Is it advisable to use the external crystal for better timing accuracy and long-term stability?
• Or is the internal clock sufficiently reliable for CAN J1939 and CANopen communication in a production environment?

[mƎALLEm]

Hello @sasmitjoshi5 and welcome to the ST community.

No matter CANOpen is used or not. It's recommended to use a Crystal with CAN/FDCAN especially for industrial environment otherwise you will face some communication issues.

See also: Do I need an external crystal for RS485 or CAN on STM32H533RET6?

Hope I've answerd your question.