compenstation cap for 2nd order allpass delay circuit

Status
Not open for further replies.
2 questions regarding this circuit.
Does it need a stabilitly cap to stop hf oscillations?
How is the input impedance calculated?
 

Attachments

  • 2nd order allpass.JPG
    2nd order allpass.JPG
    103 KB · Views: 75
It needs a cap only across the feedback resistor of the second OPA. With the aid of a square wave generator (at 10KHz) and a scope connected in output,try values between 22pF to 220pF to find where the overshoot of square is eliminated.
For the input impedance calculation, you may ask the help of AndrewT.
 
Status
Not open for further replies.