[sdiy] How to use an analog time-domain multiplexer?

[Michael Zacherl]

> On 04.06.2021, at 10:49, Tom Wiltshire <tom at electricdruid.net> wrote:
> 
> 
>> On 4 Jun 2021, at 09:42, Michael Zacherl <sdiy-mz01 at blauwurf.info> wrote:
>> 
>> 
>>> On 04.06.2021, at 10:14, Tom Wiltshire <tom at electricdruid.net> wrote:
>>> 
>>> For the bandlimiting filter, I don’t think it matters so much.
>> 
>> Hi Tom, I don’t see why not?
>> What CC describes is the same process before an A/D-conversion and after a D/A-conversion, just without the binary part.
>> And IMHO of course Nyquist-Shannon applies here.
> 
> Yes, of course it does. All I meant was that I don’t think the bandlimiting filter is so fussy about whether it should be Sallen-Key or MFB or whatever. For the reconstruction filter, I can see reasons why it should be MFB.

ok, I hear you! I just don’t see a Sallen-Key filter being used for “brick-wall” duties. 

> But definitely both filters are needed, and this is exactly a sampling process without the ADC/DAC step.