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Oscilloscope input filters
Posted: Thu Jun 19, 2014 10:18 am
by Crt Valentincic
Originally posted by Andrey Sobol:
Hi guys,
How can I calculate coefficients for input filter from basic ones a0,a1,b0,b1 IIR or FIR filter?
Re: Oscilloscope input filters
Posted: Thu Jun 19, 2014 1:37 pm
by Crt Valentincic
More detailed information about input filter can be found here:
http://wiki.redpitaya.com/index.php?tit ... ifications
Re: Oscilloscope input filters
Posted: Mon Jun 23, 2014 11:13 am
by Crt Valentincic
We believe the response you attached is correct. The applied filter coefficients introduce a pole and a zero at kHz range (we call that equalization filter). The smoothing filter is here disabled (pp=0).
You can better visualize that by replacing the plot function with semilogx. The equalization filter is used to cancel out extra poles and zeros introduced by probes or capacitive dividers.