Isolated CAN Transceiver ADM3053

[wilfergalsen]

...
hello.
I am trying to understand an integrated circuit ADM3053. Is an isolated controller area network (CAN). I have a question that you can help me solve. The recommended applications: put a resistor between CANH and pin CANL. My question is, What role does this resistance? and it is important to place the resistance? Thank you very much for working with your time.


Wil

 

[embpic]

yes in between CANH and CANL signal there is use of terminating resistor of 120 ohm and normally where there is differential line signalling then most of the bus use this resistor.
and this resistor use to limit the wave reflection at high frequency.

 

[bigdogguru]

Proper termination of a CAN is required to reduce or alleviate signal reflections, the three standardized methods of properly terminating a CAN network are depicted as follows:



The most commonly utilized method, often referred to as standard termination, depicted in the first case requires a 120Ω resistor at each end of the CAN bus.

BUS TERMINATION

Bus termination is used to minimize signal reflection on
the bus. ISO-11898 requires that the CAN bus have a
nominal characteristic line impedance of 120Ω. There-
fore, the typical terminating resistor value for each end
of the bus is 120Ω. There are a few different termination
methods used to help increase EMC performance (see
Figure 11).

1. Standard Termination

2. Split Termination

3. Biased Split Termination

The following appnote discusses in depth the CAN bus physical layer:

AN228 - A CAN Physical Layer Discussion

The following appnote delves into the other layers of the CAN protocol:

AN713 - Controller Area Network (CAN) Basics



Out of curiosity, what specific application of your design requires the robustness of the ADM3053 CAN Transceiver?

Have you considered a less costly CAN Transceiver, like the Microchip MCP2551, MCP2561, etc?

If you are just beginning to delve into CAN design, the MCP2551 would be much less costly and simpler to utilize/implement in a design.


BigDog