1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Describing sensors from datasheet information

  1. Mar 11, 2014 #1
    There is a graph of voltage gain against frequency...but it seems like for a gain of 1, that the gain increases after a certain voltage... I know that that doesn't make sense and there is something I dont understand. I have attached a doc with the image from the datasheet in it.
    How do I describe?!

    Thanks!
    Melanie
     

    Attached Files:

  2. jcsd
  3. Mar 11, 2014 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    The top trace is the open-loop gain and the bottom trace is the closed-loop gain with unity negative feedback.

    The closed-loop gain can peak at some higher frequencies due to capacitive elements within the device producing some positive feedback. They don't show up at low frequencies because the capacitances look like open circuits at those lower frequencies.

    The open-loop feedback should exhibit steeper slopes as the peaking frequencies are approached. The open loop is of course not data but just a Bode plot whereas the closed loop might be actual data. Only you know for sure ...
     
  4. Mar 13, 2014 #3
    Hi rude man
    thank you very much!!

    Iv'e attached a datasheet http://www.ti.com/lit/ds/symlink/ina111.pdf .... since there are more than one lines on the graph, what does this mean the graph is showing?
     
  5. Mar 13, 2014 #4

    berkeman

    User Avatar

    Staff: Mentor

    Welcome to the PF.

    Since this is your schoolwork, you are required to show some effort in answering the questions. What do *you* think is meant by the different traces on the graphs? What specifically is the schoolwork question asking for?

    And the datasheet is for an Instrumentation Amplifier, not a sensor. Can you clarify?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted