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FDCAN communication circuit on STM32h745/50 Disco Board.

Associate II

Hello Experts,

My goal is to send data between stm32h745 and stm32h750 disco board via FDCAN.

However, I am not sure if this circuit works properly. Also, I don't have any CAN analyzer/tool in my hand now.

So, I have doubts regarding the circuit for FDCAN for both boards.

I checked the user manual and looked at the FDCAN schematics on both boards (here is the link to the user manual, on page 38)

From my point of view, there is no need to add the extra CAN transceivers and 120-ohm resistors because there are already on both boards. 0693W00000QNSv0QAH.png 

the U22 is a CAN transceiver, and R224 is a 120-ohm resistor.

So, later I just need to connect the pins from CN11.

0693W00000QNSvFQAX.jpgThe CANL from both boards is connected, and the CANH from both boards is also connected. Totally, only 4 jumper wires are used.0693W00000QNSvUQAX.jpg0693W00000QNSveQAH.jpgPlease give me some tips or some advice, Thank you!

Patrick Lin

ST Employee

It's OK to connect CANH/CANL for both board and add 2 120 ohm for End point.

But please take care the FW solution.

ST Employee


Connecting H-to-H, L-to-L through the 2 pin connectors as you mentioned like CN2.

Fit the Jumper JP7, and also another Jumper on the board to keep the two 120ohm connected.

And yes, no extra can tranciever is needed.