high freq vco

[Magnus Danielson]

From: René Schmitz <uzs159 at uni-bonn.de>
Subject: Re: high freq vco
Date: Mon, 14 Aug 2000 03:00:36 +0200

> At 02:21 14.08.00 +0200, Magnus Danielson wrote:
> 
> >http://www.semiconductors.com/pip/NE_SE566
> >
> >I note the feature:
> >
> >* Frequency adjustable over 10-to-1 range with same capacitor 
> 
> Right, when you use a resistor as a "current source" - poor compliance. But
> a transistor source has much better compliance than that. Been there.
> 
> >Anyway, there is an PDF so you can fetch that and have a look. The internal
> >topology is featured. No SPICE model as far as I can see.
> 
> Thats the most interesting part, you realize that the "timing resistor" pin
> is really just a current input.
> You wouldn't want to sweep using the modulation input.

Yes, in this aspect is it up the similar lane as we have with the good old
4046 VCO section's input. Pin 6 of the NE 566 is really the reference current.

Cheers,
Magnus