Hi Friends,

I came across a burr-brown app-note where a schematic of precision Full wave rectifier operating from single supply is given. Given below is the schematic.



The recommended opamps for above are opa2237, opa2336, opa2340. In the same paragraph it is also mentioned that For this circuit to operate properly the inputs of A1 must remain high impedence within the entire operating range of the absolute value circuit and of course the opamp outputs must swing to negative supply rail on input and output without phase inversion. This condition is satisfied by many CMOS, JFET and some BIPOLAR input opamps.

I have already sent a quotation request for OPA2340 to see if it fits in my budget. In case it does fit in my budget should I make an exact copy of circuit as shown in above schematic? I am really scared of single supply op-amp operation after reading several scary notes with regards to instability. In case it doesn't fit in budget I will have to stick to TL082. I want to know can I use TL082 in the above circuit with supply say +12,0. TL082 has JFET inputs. If someone says yes I will try that circuit by tommorrow and let you guys know the performance.

I will be very thankfull if someone can give me a link/pointer to single supply precission full wave rectifier using easily available opamps such as TL082 etc. Several handheld battery powered instruments such as multimeters operate from single supply and do the precission full wave rectification using TL062/TL082.

Thansk & Regards,
Prahlad Purohit.