[sdiy] Mux question on SEB's Fat controller

[Seb Francis]

>>
>>  I was looking at Seb's Fat Controller design and was wondering if the
>> voltage generated by the DAC's output going the mux is being held by the
>> MAX306 . Even when you change the mux address? Meaning does it have a sample
>> and hold function built in ? Or is the MCU cycling  so fast through all 16
>> values that they all appear to be present ?
>>     
>
> Look at the schematics closer. Signals from MAX306 go to S&H
> sub-circuits. DAC and MUX update times are fast enough, so no
> significant drooping happens.

Yes, and also to consider is that the S&H caps are large enough so the 
charge injection from the MUX switching doesn't upset the CVs much, but 
not so large that they can't change voltage quickly when 
charging/discharging through the on-resistance of the MUX.

Seb