ADR444 Incorrect Output Voltage

I am trying to use the ADR444 as a 4.096V reference for the ADAS3023, using the AD8031 as a buffer, as suggested on the ADAS3023 data sheet.  The ADR444 is giving about 4.3V, which is dropping to 4.2V after the AD8031.  Both of these are operating off 5V input.

I don't know that this will be a major issue, but I wonder if it's possible I'm missing something.

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  • Kris,

    This seems to have solved the problem!  I have been doing this on a PCB but luckily the AD8031 footprint allowed a 0R bridge directly to the ADAS3023.  Before making the bridge, I was getting 4.096V from the ADR444, and after the connection, I was still getting 4.096V.  Thank you for your help!

    Do you understand what was causing this?  Could it be a bad chip or is it something I should have spotted in the datasheets?  In case you feel like offering more insight, I'm including the original schematic for this part of the board.  The ADR434 is now the ADR444 and it has a 0.1uF capacitor on the output, and +IN and OUT pins of the AD8031 are now connected while the chip itself is gone.

    Thanks again,

    David

Reply
  • Kris,

    This seems to have solved the problem!  I have been doing this on a PCB but luckily the AD8031 footprint allowed a 0R bridge directly to the ADAS3023.  Before making the bridge, I was getting 4.096V from the ADR444, and after the connection, I was still getting 4.096V.  Thank you for your help!

    Do you understand what was causing this?  Could it be a bad chip or is it something I should have spotted in the datasheets?  In case you feel like offering more insight, I'm including the original schematic for this part of the board.  The ADR434 is now the ADR444 and it has a 0.1uF capacitor on the output, and +IN and OUT pins of the AD8031 are now connected while the chip itself is gone.

    Thanks again,

    David

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