I want to measure the RMS value of a microphone's output voltage (to get the SPL value in dB).
I see a lot of RMS-to-DC IC seem to do that but I am wondering :
At a given moment, if I read the output of the RMS chip (on an ADC), is the RMS (the average/mean part) calculated on the last 10ms ? 100ms ? 1sec ?
In other words, I want to read the RMS value every second. So I want it to be representative of the last second that just passed not the last 10ms.
How is it related to the "settling time" parameter (if it is) ?
Thank you both for your help !
Indeed the AD636 datasheet speaks of "averaging time" instead of "settling time" on the AD737 (or did I read it wrong ?) witch is what I was looking for.
And considering the price difference between an AD636 and an ADAU1701 I am truly considering going for the DSP.
Thanks again for your precious help.