Post Go back to editing

AD5263 I2C shutdown bit (SD) affects other channels.

Hi,

Is there an errata on the AD5263 part?

I have the AD5263 configured to use the I2C so I can use the (SD) shutdown bit

on individual pots.  There is a write sequence that causes pots to shut down

that are not being accessed.

1) Set all pots so SD bit equals 0. Not shutdown. Values set to 255. (Don't think the value matters.)

2) Write any value to pot 0 with the shutdown bit set 1.

3) Write any value to pot 3. Shutdown bit can be 1 or 0.

This will shutdown pot 2.  The only way to get pot 2 back is to write to it clearing the shutdown bit.

You can accomplish the same thing by doing a random access read of the channels.

Where you setup the read channel by doing a write with only the instruction byte.

You don't actually have to send a data byte.  Just writing the instruction byte in the

above sequence causes the same problem.

Thanks for your time,

Joe

  • Hi Joe,

    The issue is reported in the latest DS revision, rev F, that will be available before end of the week.

    Regards,

    Miguel

  • Hi Joe,

    We will double check your sequence and try to provide a solution for it.

    In the meantime, apologies for  any inconvenience.

    Regards,

  • Thanks for the quick response.

    I noticed that the new revision of the data sheet is posted.  The sequence I posted above is not described in the data sheet.

    What I am seeing is this.

    SHDN RDAC 1 -> Write RDAC 4 -> Shutsdown RDAC1 & RDAC3

    SHDN RDAC 3 -> Write RDAC 2 -> Shutsdown RDAC1 & RDAC3

    It appears that if I write to a different channel other than the one that causes the

    error shown above, it clears the problem.

    It would be nice if the data sheet gave a write sequence that clears the problem.  I am randomly accessing each RDAC and don't know what the last RDAC access was, the value sent or if it was shutdown.

    Thanks,

    Joe

  • Hi Joe,

    Apologies for the delay,

    As you pointed previously, we found that the sequence,

    SHDN RDAC 1 -> Write RDAC 4 -> Shutsdown RDAC1 & RDAC3, place RDAC3 in undesirable position.

    Say that, we couldn't verify the second sequence, may you provide more details of your configuration, such as teh voltages used to power the part?

    Regards,

    Miguel

  • This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin