9 Replies Latest reply on Sep 9, 2014 1:09 PM by user_14586677

    Changing PGA amplifer reference on the fly under program control

    tim.reilly

      Hi Everyone,

         

      I am using a pga in my circuits.  Most of the time I operate it at unity gain where it's input is a InsAmp referenced to AGND and the output is sent to an A to D.  However, I need to get an analog signal from a ground referenced RF crystal detector in one situation.  I mux PGA between the InsAmp and the crystal detector.  Unfortunately, I need some gain when measuing the crystal detector, but to really get much gain without driving the PGA to the rail I need a VSS reference when measuring the crystal detector. The rest of the time I want the PGA referenced to AGND.  No driver is provided to switch the PGA amplifier reference dynamically, but it can be set to VSS in the GUI.   I am assuming it can be done dynamically.  Is that true?  Could someone give me a nickel tour on how to do this for a pga placed at ACB01.

         

      Thanks,

         

      Tim