Rectifier diodes

[Scott Gravenhorst]

On Fri, 26 Jun 1998 19:09:01 +0100, "Tony Allgood"
<oakley at enterprise.net> wrote:

>Hello,
>
>Some while ago somebody was talking about diodes they could use an op-amp
>based full wave rectifier. I use 1N4148s, but are these good for rectifying
>triangle waves for frequency multiplication at audio frequencies. I am
>hoping to try some out this week. How about the op-amps? Will the trusty
>TL07X do, or should I go for OP-42s and the like? Anyone built a good
>rectifier that minimises fundamental bleedthrough?

Walter G. Jung's _IC_Op-Amp_Cookbook_ contains several circuits for
'precision' rectifiers.  Is this what you are looking for?

Also, is the bleedthru due to assyemtry/distortion in the original
signal or the turnon threshhold of the diode?

The book says that with a 741, the halfwave circuit is useful to 1khz.
Faster opamps provide better speed, a 301A is useful up to 100khz.  Op
amp selection is very important, high slew rate precision amps would
be best.

Helpful?

Excellent book.  ISBN 0-672-22453-4

-- Scott Gravenhorst
-- FatMan Site: www.teklab.com/~chordman