Re: Peak detector
Thank you all for you help. Now I understand this thinks much better. But I still don't understand something. I tried to use OP238 with slew rate 15V/us. Now if I have wrong please correct me:
I have single supply +15V. And sinus wave input signal with magnitude 5V. Now... maximum frequency of my peak detector is determinated by slew rate of op amp. So It take around 0.3us that soutput signal from op amp reach from zero to 5V, and 0.3us that signal reach zero again. That is 0.6us together. Frequency is then a little more that 1,5MHz. For me, if i understand , this is my maximum frequency limit. But my problem is - i consider also all mentioned solution above - that my peak detector doesn't work to this frequency. My peak detector wotks just to around 20KHz. I am newbie and I do not know how to solve this problem, but I assume that I have problem with saturation.
Thanks for your help!
Mathias
Added after 1 minutes:
I forget to say that I haven't try peak detector with buffer yet, because I wish to understand first circuit for the beggining.
Thank you again.
Mathias