AD5443 DAC buffering

Hello- We plan to use eight AD5443 DACs to produce waveforms. The AD8034 op amp will be used to level shift the output. What is the recommendation in terms of buffering the reference voltage, given that there are 16 loads? Thanks and Best Regards, Tim Starr on behalf of CT@AN

  • 0
    •  Analog Employees 
    on Oct 27, 2017 12:25 PM

    Hi Tim,

    Can you please provide the schematic? Do you plan to use a single reference device for the eight DACs rather than each of the DAC?

    Cheers,

    Ivan

  • Hi Ivan-

    No schematic yet...still in the architecture stage. But having only one reference was our idea. Let's say our 10V reference can put out +/-20mA. That should be enough for the 16 loads of approximately 10KOhm. But is there a problem with them all sharing the same reference output, analogous to the charge injection which ADCs experience when sampling?

    -Tim

  • 0
    •  Analog Employees 
    on Nov 7, 2017 8:07 AM

    Hi Timothy,

    Apologies for the late response. There's no charge injection behavior in MDAC's reference input as there's no sampling capacitor used. Additionally, there would be no load change as the input reference's load is code independent. But the switching artifacts during code changes might be coupled through the reference going to other DACs.

    Cheers,

    Ivan