• State Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 3 answers
  • Subscribers 46 subscribers
  • Views 269 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

DAC7716: reference voltage and output relationship

Allen Lu
Intellectual 1960 points
Part Number: DAC7716

hi team:

 i would like to confirm with that  if i set the Vref as 2.5V, and output ±10V ，is there any setting need to pay attention ? 

 tks in advance.

  • 0
    TI__Mastermind 30908 points

    Hi Allen,

    I would take a look at the following sections in the datasheet:

    The transfer functions are given and there are details about how to set the output range based on your reference. 

    You need to have a reference of at least 5V with a gain of 4 to get a ±10V output voltage range. 

    The max value with a reference of 2.5V is ±5V or 0-10V. 

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    TI__Intellectual 1960 points

    hi Katlynne:

     tks for your comments！ would you kindly help to review this SCH as attached? tks in advance!
    DAC7716 SCH Review.pdf

  • 0 in reply to Allen Lu
    TI__Mastermind 30908 points

    Hi  Allen,

    It looks like you have the UNI/BIP-A and B lines tied to 3.3V. This will put the outputs in unipolar mode. Is that what you want? Earlier you were asking about the ±10V range.

    SGND-0/1 need to be connected to REFGND-A at some point in your schematic. I don't see that on this page. 

    The VMON pin is an output pin, so you don't want to connect it to AIN. You can leave it floating if unused. 

    The MONITOR Register determines which analog signal is monitored by VMON:

    Otherwise, the schematic looks ok to me. Be sure to follow the layout, power supply, and reference recommendations given in the datasheet:

    Best,

    Katlynne Jones

  • 0 in reply to Katlynne Jones
    TI__Intellectual 1960 points

    hi Katlynne:

     tks for your suggestion.

    Katlynne Jones said:
    It looks like you have the UNI/BIP-A and B lines tied to 3.3V. This will put the outputs in unipolar mode. Is that what you want? Earlier you were asking about the ±10V range.

    i set the REF A/B as 5V, do we need to set the UNI/BIP-A and B lines as 5V also?

  • 0 in reply to Allen Lu
    TI__Mastermind 30908 points

    Hi Allen,

    Sorry for the confusion. You want to connect the UNI/BIP-A and B lines to IOVDD or GND. In your case, IOVDD is 3.3V so that is what you should connect them to. 

    My question was, are you trying to use the bipolar range or unipolar range? You asked earlier in the thread about the ±10V range, so I thought you wanted to use the bipolar mode. In that case you should connect the UNI/BIP-A and B lines to ground. If you want to use the unipolar range then you should connect the UNI/BIP-A and B lines to IOVDD.

    It looks like you have the GND resistors not populated and the UNI/BIP-A and B lines are connected to IOVDD. This will select the unipolar range. If that is what you intended then there is no issue. 

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    TI__Intellectual 1960 points

    hi Katlynne:

     Tks for your explanation. Yes ,we make a optional choice to select different mode.

  • +1 in reply to Allen Lu
    TI__Mastermind 30908 points

    Hi Allen,

    Ok great, I just wanted to make sure. 

    I'm going to close this thread for now. If you have any other questions, feel free to reply here or start a new post. 

    Best,

    Katlynne Jones