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AD8237 EEG Example

Question asked by NullPoints on Feb 2, 2018
Latest reply on Feb 19, 2018 by jrombola

Hi ADI team!


I have a few questions about the EEG example in the AD8237 datasheet.

  1. See red box below. Is the 47nF capacitor creating a LPF? Is the fc=33.8Hz? ... I'd like to use the AD8237 with a gain of 201 and a LPF with a fc of ~500Hz. Would you recommend using a 200kOhm resistor with a 0.015uF cap?
  2. See blue box below. Is the 3.3uF cap and 2MOhm resistor forming an integrator and acting as a HPF with a fc=0.02Hz? If so, I'd like to do the same but have a fc=20Hz. What cap/resistor values would you recommend in that case?
  3. See green arrow below. What cap value would you recommend for this filtered voltage divider?

AD8237 Annotated Schematic