MAX3227 experiences communication abnormalities

Hello,

Thank you for your inquiry. I would be happy to help. Could you explain the issue to me in more detail, please? Some specific questions I have are:

When you mention the TX pin of the MAX3227E, are you referencing T1OUT or the UART6 TX connection shown in your schematic?

How do you know a failure has occurred? Is the TX stuck high, low, or at ground, or is there something else that happens?

Is the part damaged when a failure occurs, or does power cycling fix the issue?

What happens right before the failure? For example,.is it normal operation or after some specific type of testing?

Is this a new design or something already in production for some time?

Thank you,

Shasta

Hello,

Thank you for this.  I have a couple more questions:

(1) Can you confirm that you bought these parts directly from ADI, or an authorized distributor?

(2) I do not see any ESD protection components on the T1OUT or R1IN lines. Do you have any ESD protection on the board?

(3) Are you connecting the MAX3227 to another device over a long cable, or some other way? 

Thank you,

Shasta

Thank you for your response. 

Unfortunately, given the information we have, I cannot offer a definitive solution, or a clear explanation of the source of the problem. My understanding is that 2 boards out of a batch appear to be damaged at initial testing.  At this point, my inclination is that the part is damaged either during testing or assembly and this is likely as ESD issue.

I would recommend adding protection components on the RS-232 lines to ensure that the part is not damaged under normal operating conditions. Additionally, please ensure that ESD protections are in place during assembly.  Please ensure that voltage and current levels on the IC do not exceed the Abs Max Ratings at any pin, but especially at T1OUT and R1IN.

Thank you,

Shasta