Analog Multiplexing with ADC: A Viable Solution?

Click For Summary

Discussion Overview

The discussion revolves around the feasibility of using analog multiplexing in conjunction with analog-to-digital converters (ADCs). Participants explore the potential applications and limitations of this approach, particularly in the context of signal processing and circuit design.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question the feasibility of using ADCs for multiplexing analog signals, suggesting that the functions of ADCs and analog multiplexers (MUX) are fundamentally different.
  • One participant asserts that multiplexing multiple analog signals and feeding them to an ADC is a common practice, highlighting the use of MUX in sample and hold circuits.
  • Concerns are raised about the compatibility of MUX with sigma-delta ADCs, specifically regarding the switching rates of the MUX in relation to the ADC's clock speed.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of using ADCs for multiplexing. While some acknowledge that it is a common practice, others question its viability, indicating that the discussion remains unresolved.

Contextual Notes

Participants mention specific conditions regarding the use of MUX with ADCs, such as the importance of switching rates and impedance, but do not provide a consensus on the overall feasibility.

dyordyen
Messages
12
Reaction score
0
Is it possible? Feasible?
 
Engineering news on Phys.org
So a bunch of separate ADCs, some network hardware and a bunch of DACs and output amps?
Any reason to do this rather than just an analogue MUX?
 
dyordyen said:
Is it possible? Feasible?

The function of an Analog-to-Digital converter (ADC) is nothing like an analog MUX function. What are you trying to do?
 
Using only ADCs? No, it's not possible.

- Warren
 
Oh wait, I'm sorry... I meant, multiplexing multiple analog signals then feeding it to an ADC...
 
dyordyen said:
Oh wait, I'm sorry... I meant, multiplexing multiple analog signals then feeding it to an ADC...

Yes, that's done all the time. You use the MUX as the sample part of your sample and hold circuit, with the hold cap between the MUX and the ADC input. The sample time depends on the impedance of the MUX switches.
 
dyordyen said:
Oh wait, I'm sorry... I meant, multiplexing multiple analog signals then feeding it to an ADC...

berkeman said:
Yes, that's done all the time. You use the MUX as the sample part of your sample and hold circuit, with the hold cap between the MUX and the ADC input. The sample time depends on the impedance of the MUX switches.

but don't do that with a sigma-delta ADC, unless the MUX switching rate is far, far slower than the clock for the sigma-delta ADC.
 
Thanks guys :)
 

Similar threads

Analyzing pushbutton switch ADC circuit edge cases
  • · Replies 4 ·
Replies
4
Views
2K
Can all the multiplexers work for any number of variables given?
  • · Replies 1 ·
Replies
1
Views
1K
Is a Multiplexing ADC the Best Solution for My University Project?
  • · Replies 3 ·
Replies
3
Views
2K
How to record two signals simultaneous(by using ADC) ?
  • · Replies 16 ·
Replies
16
Views
9K
Design 12:1 2.0 USB Multiplexer | Matija
  • · Replies 6 ·
Replies
6
Views
3K
Frequency Division Multiplexing in Telephone
  • · Replies 7 ·
Replies
7
Views
4K
Analog multiplexer - resistor at input
  • · Replies 11 ·
Replies
11
Views
7K
Protecting PCB, multiplexers and MCU in vending machines
  • · Replies 11 ·
Replies
11
Views
2K
How to connect audio output to an ADC
  • · Replies 10 ·
Replies
10
Views
3K
Analog Engineers - Look at Middlebrook
  • · Replies 5 ·
Replies
5
Views
2K