I2C bus sensitivity to electrical noise

[amn1952]

Hi Forum,
I have an I2C bus electrical noise sensitivity problem.
I have a system that connects 2 products using the I2C bus via a cable. I use an I2C bi-directional extender IC P82B715 on one of the products. The I2C protocol gets corrupted when I appply the Electrical Fast Transient (EFT) Test per the EMC Standard EN61000-4-4.
I have tried shielded cables and caps on the lines but with little affect.
Has anyone on this forum worked with I2C products and maybe be able to advise on the best method to suppress this noise that would alow the I2C bus to operate during the EFT test? e.g.
Good EFT devices?
How best to shield the I2C?
Other?

 

[melone]

What kind / size caps?

 

[cbarn24050]

Hi, you cant run 5v signals down long cables from cmos devices.

 

[amn1952]

Melone asked for kind/size of caps. I use 1nf ceramic caps.

ps. I not sure if this is the correct way to personally reply to a question asked on my thread?