LTspice subckt model for CD4046 (SED) - VCOala4046.pdf
 

On Wed, 13 Oct 2010 14:06:25 -0700, Jim Thompson
wrote:

Does anyone have a transistor-level schematic of the CD4046 VCO?

The datasheets are crocks... can't work as shown. But the general
scheme implies that someone did a copy attempt of my vintage (mid
'60's) MC4024 core (which was actually current mode).

If someone has a working unit, take a snapshot of the voltage across
the VCO capacitor.

Thanks!

...Jim Thompson

I'd expect something like as shown in the attachment.

If someone has a real 4046 to measure and can measure all the
breakpoint voltages, I can roll a model that will run on most any
Spice variant.

...Jim Thompson
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