Multiple channel sampling

[Joana]

I'm designing a board and I have multiple analog channels witch I need to sample with the same A2D.
So far, The only solution I thought of, is to use MUX and allocate a time slot to each channel and then sample it. before i'll start with these way, i want to ask if there is another way to deal with this problem, and if there is(that's my bet) , i'll most appreciate, if someone can point me to other methods.

Joana

 

[dick_freebird]

Mux is the usual way, realize you will be decimating the
data before sampling. You could also get more ADCs
and interleave the digital instead, this will let you use
a lower bandwidth ADC (but more of them) and may
be a more accurate solution overall (losing mux error
terms). The mux will cost settling time, channel
leakage current errors, etc. If you are digitizing in
differential mode then you will need two muxes so
your inputs see balanced impedances, etc.

However analog mux piece-parts often provide nice
secondary features such as overvoltage protection
that a "resource" ADC in an ASIC or FPGA or even
a standalone ADC, would not.

 

[Petre Petrov]

Hello!

Analog Devices, Maxim, National semiconductor, Texas instruments, etc have a lot of application notes on the subject.
May be they could be useful for your case.

e.g.
Fundamentals of Sampled Data Systems Application Note (AN-282)
https://www.analog.com/static/impor...368301086579520703792632610264805090AN282.pdf

**broken link removed**

https://eu.wiley.com/legacy/wileychi/hbmsd/pdfs/mm452.pdf

But the topic is complicated.

Good luck!

BR