1 Reply Latest reply on Dec 2, 2008 7:54 AM by fazil.duman

    amplifier noise

    stephen.taylor
              I am considering using a PSoC device as part of an instrumentation system, but am worried that the amplifier ac specs may not be up to the job. I need an instrumentation amp with gain of about 20-50, low bandwidth (up to 50kHz GBW) and low input noise (<5uV). The INSAMP quotes 0.75MHz GBW at 5V and a noise voltage input of about 100nV/rtHz, which would yield an input noise of 12uV at G=50. This is too high. Has anyone obtained actual noise figures for their similar designs please?   
        • 1. Re: amplifier noise
          fazil.duman
                  stephen, not only instamp but also adc has its own noise,   
          you have to take care of 2 things,   
          1. offset voltage error   
          2. common CMMR   
             
          if you look at 5uV is high noise, i addvise you to use external instamp like ad623, and also be careful about adc,   
             
          if you are working on a signal at about F hz, than sample it minumum 2Fhz (much is better) than apply moving avarege filter,   
             
          it wil give you the average noise of the system, the remove this noise to the every sample you get,   
             
          it is not the best solition but it works in high frequency.