TCAN1042H: Tcan1042: how to calculate the characteristic impedance of termination

Miles Li1

Part Number: TCAN1042H

Dear team,

I would like to know how to calculate the termination resistor? How do I decide which termination way should be included? Standard termination or just split termination?

Wish to get your reply as soon as possible. Thanks!

over 3 years ago

0 Eric Hackett over 3 years ago

TI__Guru 60042 points

Miles,

If the CAN node is going to be an node at either end of the bus, the termination impedance should be 120 ohms. In most cases, the split termination is the preferred method since it comes with low-pass filtering, helping with the signal integrity of the CAN bus.

If the CAN node is not an end node, depending on how long the conductor connection to the CAN bus will determine if the node needs termination resistance or not. And the termination resistance will depend on how many CAN nodes are on the bus.

Can you share a bit more information about your application? How long is the CAN bus (physically) and how many nodes do you expect to be on the bus?

Regards,