Online searchable catalog of re-useable circuit designs?

[Stephen Durr]

In the software world they call these things "design patterns", and they are meant to prevent people from reinventing the wheel.  For most applications there probably already exists a well-designed pattern that works out of the box or at least provides a good general foundation on which to build.  Is there any such similar thing for electronic circuit designs?  I think in the past there were paper books like "Encyclopedia of Electronic Circuits", etc., but after a time paper books become out-of-date or the printed designs become superseded by newer designs based on newer components and/or techniques.  So I am wondering does such a thing exist on the web?

[ivan747]

Usually this is the functionality of integrated circuits. But also, you can find common circuit blocks in app notes from the different component manufacturers.