• State TI Thinks Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 3 answers
  • Subscribers 34 subscribers
  • Views 104 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MAX3222: MAX3222CDB

RAMKUMAR R
Prodigy 50 points
Part Number: MAX3222

Tool/software:

Hi TI,

We are currently using the MAX3222CDB part in our product, which has now been marked as obsolete. Texas Instruments has recommended MAX3222EIDBR as the replacement.

During the technical comparison, we observed that:

The old part (MAX3222CDB) supports a data rate of 150 to 250 kbit/s
The new part (MAX3222EIDBR) supports a data rate of 250 to 500 kbit/s


My Questions:
1. Why is there a difference in the supported data rate range between the two parts?
2. Can we safely replace the old IC with the new one in our design?
3. What potential impacts or risks should we be aware of with this change?

We are looking forward to your support. 

Thanks,

Ramkumar R

  • 0
    TI__Guru 52242 points

    Hi Ramkumar,

    For your questions:

    1. Our suggested replacement device is a different device - typically the "E" suffix just means better ESD but on some devices other changes were made. We don't have a ton more information than that because the device is almost 20 years old so we don't all the information why this change was made - just that it was. 

    2. There really shouldn't be any risk as you can still go the slower speeds - its just now you would also be able to go faster than you used to with previous device - I'd still advise you test the new device - we don't specify every single parameter that may impact system so in those edge cases I'd still suggest a test  also if you use ICT for validation of the board the values could be different when measured-  but we don't anticipate any major issues by replacing the IC with the new suggestion. 

    3. The biggest thing that I haven't already mentioned in point 2 is that since the device is faster you could see a little more energy concentrated at a higher frequency band - that being said this really isn't a problem because both parts are extremely slow so I don't think EMI should be a major concern - it typically isn't with RS-232. 

    Please let me know if you have any further questions and I will see what I can do!

    Best,

    Parker Dodson

  • 0 in reply to Parker Dodson
    Prodigy 50 points

    Thanks for the details, can you please confirm the you suggested replacement?

  • 0 in reply to RAMKUMAR R
    Prodigy 50 points

    Also, please confirm whether we can use the new device for applications requiring speeds below 250 kbit/s. If yes, what is the minimum supported speed?

  • 0 in reply to RAMKUMAR R
    Guru 316860 points

    I can cofirm that the suggested replacement indeed is the suggested replacement.

    250 kbit/s is the guaranteed maximum data rate; you can also use any lower rate. (An idle RS-232 bus has a data rate of 0 Hz.)

    500 kbit/s is a typical maximum data rate; it is not supported by all chips at all temperatures. Ignore it.

  • 0 in reply to Clemens Ladisch
    Prodigy 50 points

    Hi Ladisch,

    Thanks for the details.

    Could you please explain once again briefly. i couldn't understand.

    Thanks,

    Ramkumar R

  • 0 in reply to RAMKUMAR R
    TI__Guru 52242 points

    Ramkumar,

    The device we suggest as the replacement is the device you should use. It is a different die though so that is why we still suggest testing it to make sure there are no issues - but we don't have a closer device than the one that is suggested. 

    What I imagine Clemens point on the 500kbps  is that the spec really doesn't mean anything. It is a typical spec which are never guarantees - the minimum data rate is what you should be designing applications around which is 250kbps - in many scenarios you could push it to 500kbps - but I wouldn't build the application around it and keep at 250kbps. However since the device you are switching from is slower this isn't an issue for your design. It is specifically spec'd for 1000pF as well  - the data rate could be slower if higher bus capacitance is used.

    Best,

    Parker Dodson