[sdiy] small VCO core (was Temperature stable lin-exp converter with a CA3086 or CA3046)

[Ian Fritz]

There are indeed several advantages to using a TRI core. The CEM3340 
literature explains these quite well. The TRI #2 VCO on my site has 
excellent performance mainly due to not using an OTA chip and to using 
high-quality modern components. I also show a novel TRI-SAW shaper with 
only miniscule glitches at the switching points due to the switches being 
driven from the VCO core directly rather than from derived signals. T 
compensation is also discusssed.

   Ian

   http://home.earthlink.net/~ijfritz/sy_cir4.htm



At 11:55 PM 5/27/2002, jorgen.bergfors at idg.se wrote:

> > It would be nice to have a core VCO design. Just an
> > expo convertor and a sawtoth oscillator.
>
>Why sawtooth? My recent experiments show that it is much easier to shape
>other waveforms from a triangle core.
>Also, a triangle VCO doesn't have the problem with the sawtooth reset time.
>Mine stays in tune to over 20kHz, without any HF compensation whatsoever.
>
>/Jorgen