I'm trying to add 4 output of ADA8282 together and create only one analog signal with bandwidth about 6 MHz, I know Op-Amp adder as "How can I add three AC signals?" and "ElectronicTutorial" said. Also someone in "How can I add three AC signals?" called for analog multiplexer and inspired me this: multiplex at 4xbandwidth of signal, then LPF to 1/4, tada, the answer will be average of all 4. but these are not reliable need work, design and time, but i want reliable firm timeless solution, exactly an IC that do this for me is it available? and why, if not. Is adding signals are not commonly used?!why? Are everybody uses the Op-Amp method?
2 Answers
This is a little unclear what you are actually having problems with, but I'll try:
Is adding signals are not commonly used?!why? Are everybody uses the Op-Amp method?
It's very common, and it's so common that an IC was designed to do it: The operational amplifier, which can do operations such as summation - exactly what you want! How to do so is explained in one of the answers you linked to.
multiplex at 4xbandwidth of signal, then LPF to 1/4, tada, the answer will be average of all 4
Well... yes, but you would need a very good filter for this to work, in combination with multiplexing at a much higher frequency. It is not really useful compared to a simple OP-amp adder.
You could use 3 simple OpAmp Adders to add 4 inputs called A,B,C,D. Signals A and B would go into adder 1, and signals C and D go into adder 2.
Then the adder outputs of 1 and 2 go into adder 3.
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\$\begingroup\$ Gratefully, can you explain more, and mention some exact part? since in reference called "ElectronicTutorial" told: you can add multi signal with only one Op-Amp. \$\endgroup\$ Commented Nov 24, 2018 at 6:50
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\$\begingroup\$ Sorry, my mistake. I was just brainstorming.. It was not much of a solution. \$\endgroup\$ Commented Nov 26, 2018 at 4:40