Newbie here. I need a bit of help from someone with a good knowledge of using op amps particularly as rectifiers.

I have a sine Wave of between 0 and lets say 5 v. And a frequency in the region of 180 k hz. The amplitude of the sine wave will change upon detection of an object ( magnetic field ) From this sine wave I want to derive a D.C. voltage in proportion to the p to p value of the sine wave.

I am trying to use a precision instrument rectifier and then some smoothing to produce the D.C. signal but I am having trouble. the op amp does not appear to produce what it should at this high a frequency I think it’s not up to the job using a LM324N

any help gratefully received

regards

LesC