On Board Filtering
taylorwebb85
University of Utah
Can some one point me to documentation on any filtering happening on the board? I am guessing there is some anti-aliasing filtering before the signal is passed onto the PC? I am using the Cyton V 3-32.
Comments
No DSP filtering happens on the Cyton. The GUI recording file is raw, no filtering. But the GUI screen display filtering can be adjusted with the menus.
Right, thank you for this.
I am wondering about the characteristics of the anti-aliasing filter. There must be an analog filter before the sampling.
Taylor, hi.
Yes there is an RC filter applied to each channel before it reaches the ADS1299, required for sigma-delta ADCs. See schematic,
https://docs.openbci.com/Cyton/CytonSpecs/
2.2Kohms and 1nF. Here is an old thread on the subject,
https://openbci.com/forum/index.php?p=/discussion/154/front-end-filtering-esd-cmrr-rfi
William