SV: Re: SV: Re: SV: Re: [sdiy] VCO autotune for poly analog modular

[karl dalen]

--- Antti Huovilainen <ajhuovil at cc.hut.fi> skrev:

> On Fri, 6 Apr 2007, karl dalen wrote:
> 
> > I thought you understood my indirect sugestion?
> 
> > Anyhow, you do need high resulution and also high
> > accuracy especially for the low freq range
> 
> High resolution and differential linearity yes, accuracy no.

No, at low freq you need accuracy.
Just as in a exponetial driven VCO one neeeds that all 
parameters in DAC are good, not just average.

Actually, you dont need high accuracy, you can basically
do the Fatman trick  with a 8 bit DAC and divide down.
If you want to.

> > *Static* DC and gain can be large but not huge!
> > Unfortunately they are *temperature and code* dependent.
> 
> Code dependency goes to nonlinearity = lower resolution (I did 
> say high resolution). As for temperature, the whole idea is based around 
> autotune so any temperature dependency would be cancelled. The main point 
> is that you do not need very good offset or gain accuracy (which cost).
> 
> > Even a ancient MCU would do, i don't see the reason why the wouldn't?
> 
> You'd have trouble calculating all the modulations at > 1 kHz rate for 
> multiple VCOs.

*Where* did he say that he was going to do it in rel time?

KD


> 
> Antti
> 
> "No boom today. Boom tomorrow. There's always a boom tomorrow"
>    -- Lt. Cmdr. Ivanova
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