[sdiy] MOSFET leakage.

[Grant Richter]

If you think about it, the A/D bits are at 1,2,4,8,16 and so on,  
multiples of the sawtooth frequency.

I am pretty sure those square waves and EXOR gates are all that is  
needed for a Walsh Function Generator.

So a VCO with A/D and a CPLD would make the Walsh Functions.

On Dec 17, 2005, at 5:53 PM, Grant Richter wrote:

> I have used a 2N7000 with OK results.
>
> The VCO for the Terrain module replaces the analog comparator with  
> a 20 MSPS video A/D.
>
> The sawtooth peak is detected as the "all ones" condition with an  
> eight input AND gate.
> This sets a 4013 which drives the 2N7000 across the timing cap.
> The "all zeros" reset signal is generated by an eight input NOR  
> gate, which resets the 4013 and starts the next cycle.
>
> The rest of the circuit is Terry's sawtooth core.
>
> The advantage is that you have simultaneous analog and digital  
> sawtooth outputs.
>
> On Dec 17, 2005, at 2:34 PM, Ian Fritz wrote:
>