precision rectifier

Thread Starter

shruthi kashyap

Joined Nov 18, 2011
1
can any one tell me why the word precision is used in precision rectifier and what is the difference between precision rectifier and the normal rectifier... it`s urgent
 

MrChips

Joined Oct 2, 2009
19,382
A simple rectifier circuit uses a diode. The input voltage has to exceed the turn-on voltage (0.6V for ordinary Si diode) before rectification is achieved.

A precision rectifier is an active circuit using an opamp and a diode in the feedback loop. This overcomes the turn-on "knee" voltage.
 

Wendy

Joined Mar 24, 2008
21,906
To add to what MC said, this is useful for test equipment, where eliminating extra variables is required.
 

crutschow

Joined Mar 14, 2008
23,494
The op amp reduces the turn-on voltage of a diode in its feedback loop by a factor equal to the open-loop gain of the op amp. For practical op amp gains this reduces the forward voltage to a fraction of a mV, thus giving a "precision" or near ideal diode characteristic for the rectifier function.
 
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