Dual Polarity Peak detector 1

[Trex77]

Well, I've helped others in the forum here... this time I need some help..

Looking for circuits to use as a starting point in designing a positive and negative (bipolar) peak detector... Using a dual opamp (TLE2072, 10Mhz BW), ckt response to 500Khz is desired. Input will be from a prior stage opamp that can output pos or neg signals from a transducer. The pulse outputs are way too fast and we want the peaks and a waveform that is more of an envelope follower type so this stage will be followed by a 2nd order lowpass filter. This is to allow a much more reasonable A/D converter spec (lot slower A/D) and lower the noise floor.

Anyway looking for a single or dual opamp ckt using diodes and or transistors in support of the opamp that can feed a single R-C that is the peak detector output. Current crude uni-polar Pk detect ckt uses 0.047uF cap and a 16K resistor in shunt, cap charge is via a series 47 ohm resistor and the usual diode (1N4448) from the opamp output. Input voltages range from 0.05V to 5V pk. Power supply is +/-15Vdc.

Thanks in advance for any ckt references or URL's.

If any PDF's or scanned images, I can accept files under 25Mb via email attachements to: Rtracy77@aol.com

 

[nbucska]

What is the waveform you want to peak detect ? Accuracy ?
Is it a single unit or mass product ? (How important is the cost ?) <nbucska@pcperipherals.com>

 

[jbartos]

Suggestion: Visit

http://www.designtest.com/wpapers.html

http://www.panametrics.com/div_ndt/pages/products/instrument/5607item.shtml

http://www-cdslab.ece.umn.edu/cdslab/research/prml.html

http://www.ibelings.com/n4ip/sskw/

etc. for more info

 

[xray]

hey trex77

I hope this helps. The winning desing of the EDN magazine design ideas was a similiar device utilizing a bjt for peak detection. I'm pretty sure the device can detect pos and neg of a waveform, Amplitude Modulation, up to 5MHz. The issue was this months June 2001 bimonthly.

xray

 

[xray]

hey trex77

here is a web page from EDN with a similiar device design,

http://www.ednmag.com/reg/1994/051294/10di3.htm

later

 

[Trex77]

Thx..xray Found the same ckt a few days ago... looks like at least a place to start...just have to make it work for +/- 15Vdc supplies... looks do-able at least.

I didn't find you ref to the &quot;winner edn ideas for design&quot; unless it was that UV meter ckt...

 

[jbartos]

Suggestion: Visit

http://www.ednmag.com/reg/1994/112394/24di3.htm

for a non-opamp alternative