Hi，TI Engineers.
ISO1042-Q1 has two kinds of GND :Digitial GND and Isolate GND. I want to know wthether the two kinds GND plane should connect by a 0 ohm resistor or a capacitor. Or I need to leave these two kinds GND plane isolate throughly ?
Thank you.
Regards.
Gavin Zhang
Hi Gavin,
The GNDs should remain not-connected in order to preserve the isolation barrier. Any connection between the GNDs would bypass the isolation barrier, and so you would not see any benefits of using an isolated CAN transceiver. So do not place a 0 ohm resistor across the isolator. A capacitor across the isolation barrier is not necessary either.
Furthermore, you need to ensure that the GND layers are kept separate on your PCB.
You can see an example of a layout for ISO1042 in our EVM user guide.
On a similar topic, how are you planning on powering each side of the ISO1042? The power on each side needs to be isolated as well. I would recommend looking at the transformer driver SN6505B for isolated power. Here's an application note on how to isolate signal and power in isolated CAN systems.
Let me know if you have any questions!
Best regards,
Dan
