Tuesday, May 15, 2012

Notch filter Lt spice

This is what i am working on right now a 3rd order inverted filter. well i am trying to figure out the correct component values to have a 500Hz notch filter . while using f = 1 / 2*pi*R*C .
R=R1=R2. R3=.5*R
C=C5=C6 . C4=2*C

it is strange that the graph isn't giving me notch graph. Perhaps i did something wronge


  1. Hey Al-Yaqdhan,

    Your filter topology isn't quite right for a notch filter. Check out this LTSPICE file


    This will give you a 500Hz notch filter with only a buffer opamp. You'll need to play with the values to get resistor and cap values you can actually buy.

  2. Eric Dear thanks alot you are completly right , my topology is wronge. i will carry on with the circuit you gave me.

    keep up the good work! thanks again