8 Replies Latest reply on Dec 16, 2011 4:41 AM by kannan.sadasivam

    How to sample a microphone with best signal to noise ratio?

    christof.eberspcher

      Hi,

         

      I am trying to preamplify and sample a microphone signal, but I get a lot of noise.

         

      The microphone gives a maximum of about 3mV of signal amplitude. So at the moment I use a single inverting PGA with gain 49 and try to use lowest possible range +/- 256mV of the 16-bit Sigma Delta ADC omitting it's input buffer. The signal to noise ratio of this setup seems to be only about 6 bits.

         

      What is the best method using the internal amplifiers?

         

      Many thanks!

         

      Christof