[sdiy] PLL module

[Scott Gravenhorst]

dlmanley at sonic.net wrote:
>
>
>Hi Scott,
>
>Why is the whole circuit running between ground and -V? I was 
>looking at the JK flops with their inputs grounded, and wondering 
>if the schematic was wrong. Took a while to notice the power 
>scheme. 

This was, for me, a FatMan addon.  The VCO in a FatMan provides an output that swings
between -12V and ground.  So it was easy to just use the -12 volt supply and ground
for the logic too and made the interface simpler.  The VCO is DC coupled to the input
of the PLL.

>The other thing you can do with a PLL circuit is put a 
>programmable divider on both the input and the output feedback to 
>the phase comparator input - allowing you to get fout = M*fin/N. 
>Someone might find it useful. 

I like it.

>-Dave
>
>Apologies if this gets sent to the list twice - using a different mailer
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-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
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