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AD5791 Reference Buffer Opamps

The data sheet and reference designs recommend the AD8676 for voltage reference buffers.  I would like to use an opamp that draws less supply current than the 3.4mA max of the AD8676.  The ADA4077-2 looks to have similar performance specs, and draws only 0.5mA.  The DC specs of the ADA4077-2 are fine for my application.  But it has a slightly lower bw than the AD8676; 4MHz vs. 10MHz.  Can anyone comment if I would be risking settling time or any other performance specs by using the ADA4077?

  • FormerMember
    0 FormerMember

  I would assume the main reason they picked the AD8676 was for the lower voltage noise.  To get every last ounce of perfomance from the AD5791, you need to minimize every source of noise.  To get lower noise in a bipolar, we have to burn some current.  Your update rate and signal bandwidth would dictate if you can use the ADA4077.


  • Would an auto-zero amp like the ADA4528-1 work well here?

    Can it handle large capacitive loads and how would the spike at 200kHz affect the converter's performance?

    - James

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