I have some trouble measuring the cutoff frequency, of a simple lowpass fitler with the .MEAS command.
the command that I’ve used - .MEAS fc FIND frequency WHEN mag(V(out))=-3, this just returns nan values.
Br.
Marc H. Munkstrup
I have some trouble measuring the cutoff frequency, of a simple lowpass fitler with the .MEAS command.
the command that I’ve used - .MEAS fc FIND frequency WHEN mag(V(out))=-3, this just returns nan values.
Br.
Marc H. Munkstrup
mag(V(out))>=0 it is error.
I expect you want to find -3dB, and you are missing db() function. You was to find |V(out)|=-3, not in dB, but in linear magnitude, -3dB with linear magnitude is mag(V(out))=0.707
or use this instead :
.MEAS fc FIND frequency WHEN db(mag(V(out)))=-3
Ahh of course, its not even possible for it to be -3 dB when it is the linear magnitude.
Thank you for clearifying
//Marc