what is the current noise density vs frequency for the ADA4625

Is there a plot available?

  • 0
    •  Analog Employees 
    on Nov 10, 2017 12:13 AM over 2 years ago

    Hi Gregory,

    Let me check if we have data for this.
    But for the meantime, can you also tell me why are you interested on this graph? What is your applications? Does the current noise specs on page 6 of its datasheet won't be enough on your calculations? Usually the effect of current noise of the amplifier is negligible especially for low impedance sensors.

    Best regards,

    Emman

  • Is there any update on this topic. I too am looking for info on the current noise at low frequency. I intend to use ADA4625-1 for a unity gain buffer following a passive R-C filter ~1 MOhm + 20 uF (CDE #935C1W20K-F) and would like to estimate the noise due to the ADA4625-1 voltage and current noises in such a circuit. The filter input is from a voltage reference and the goal is of course to reduce the low frequency noise of the reference. I hope there may be a plot of current noise or info on 1/f corner of the current noise???

    BTW the datasheet for this part is really excellent! (I just wish it was slightly more excellent in including the current noise plot.)

    Thanks, sincerely,

         Gerard

  • 0
    •  Analog Employees 
    on Aug 13, 2019 9:25 AM over 1 year ago in reply to gvisser

    Hi Gerard, 

    See below for the current noise density of the ADA4625:

    Let me know if you need anything else. 

    Thanks, 

    Kris

  • hi Kris,

    Thanks that plot does give some good info to me. However also, and more particularly, I was hoping to know about the lowest frequencies, is there a 1/f component of the current noise or does it stay actually flat down to DC? A plot down to 0.1 Hz or even better 0.01 Hz would be great, or simply a typical p-p current noise over 0.1-10 Hz, or some such spec.

    Anyway, I am making some bench tests now (not to directly measure the current noise, rather just a test circuit for the application mentioned above, which I think would show the effect of any extra low frequency current noise).

    I appreciate your help, if there is any further info I will be glad to hear it. I understand if it is not possible though. Sincerely,

         Gerard