[sdiy] Interesting Charge-Pump VCO from Electronic Design magazine

[Tim Parkhurst]

On Mon, Jun 15, 2009 at 4:28 PM,
flightofharmony<flight at flightofharmony.com> wrote:
> http://electronicdesign.com/Articles/ArticleID/21195/21195.html
>
> This design is in the current issue, they claim 0-10kHz with 1% linearity
> except in the low end (below ~600Hz, judging by the graph).
> Scaling is 1V/kHz, 0V = 0Hz, 10v = 10kHz
>
> No special components, looks like it might be fun to tinker with.
>
> Components:
> (1) LM339 Quad opamp
> (5) 1N4148 diodes
> (1) 5.1V Zener
> (4) ceramic caps - 3 X7R & 1 NPO
> (10) 1/8W resistors
> (1) 100k potentiometer
>
> Best regards,
>
> ~flight
> flight at flightofharmony.com
> http://www.flightofharmony.com
>

Looks interesting. Don't forget a pull up R on that open collector
output. The output is square only, although you might be able to tap a
triangle off the timing cap (C2). You'll need an extra buffer for the
triangle, and another dual op amp for the CV summer, but you could
pull the whole thing off with one 339 and one quad op amp package.
Prolly make a good linear CV clock for a delay or something.

Tim (needs an extra buffer or two) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings