Sanctified Sinewaves: Jim Williams' Ultrapure Oscillator

[dchisholm]

Jim Williams' latest (and last) attempt at perfection.

http://www.edn.com/article/519046-Te...oscillator.php

(I have had some difficulty making that link work. All I can suggest is, "Keep trying. Sisu. Illegitimi Non Carborundum.".
Or try < http://www.edn.com/file/26070-Test_1...llator_PDF.pdf > http://www.edn.com/file/26070-Test_1...llator_PDF.pdf. )

This is obviously the effort referenced in the thread, " Jim Williams designs a new Super Oscillator".

• I see a fixed-tuned (2 KHz) Wien-Bridge variant with an analog optoisolator as the gain-control element.
• An opamp-based precision rectifier circuit is used for amplitude detection.
• The DC-offset is obviously there because of the end-application (testing A/D converters), but I don't know whether removing that feature would degrade performance.
• The 130 ohm/0.47 uF lopass network on the output calls for a little thought and investigation.
• A look at the "Notes" on the schematic tells you that "attention to detail" is important!

Dale

[mlloyd1]

i had trouble also. i did some site searching and found it:
EDN - Download

mlloyd1

[thaumaturge]

For those who haven't heard as yet we lost Jim Williams back in June. Worse yet we also lost Bob Pease of National semiconductor in a car wreck on the way back from Jims funeral. A dark day for analog as both were sage gurus. Doc