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Op-Amps suggestions for Instrumentation Amplifier

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alec_t

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You'll get greater accuracy by buying an instrumentation amplifier rather than trying to build one from opamps.
 

alec_t

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Your photo-diode may well have a 160MHz bandwidth, but what bandwidth will you actually be using?
 

crutschow

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You definitely don't want to try to built your own at those frequencies. :eek:

One listed in this search should work for you.
But it still will require careful layout and decoupling on a circuit board with a ground plane.
Don't even think about trying a solderless breadboard. ;)
 
You definitely don't want to try to built your own at those frequencies. :eek:

Don't even think about trying a solderless breadboard. ;)
Exactly, hence my search for a good op-amp or equivalent so that I can start by using demo SMT boards and try out different op-amps.
 

crutschow

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Exactly, hence my search for a good op-amp or equivalent so that I can start by using demo SMT boards and try out different op-amps.
Why do you insist on using op amps when a differential IC amp is much better suited to the job? :confused:
 

crutschow

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I meant op-amp or equivalent which includes differential amps as well, definitely not tied to using op-amps only :)
Okay.
Generally common usage of the terms is that an op amp is considered to be distinctly different from a differential amp, even though op amps do have a differential input.
 
Okay.
Generally common usage of the terms is that an op amp is considered to be distinctly different from a differential amp, even though op amps do have a differential input.
Thanks for clearing up, I never had to use differential amps till now, so not that knowledgeable in them.
 
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ronsimpson

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Eventually I want to amplify that signal (to 50dB about 500 times) and convert into single ended output.
320MHz is what I am aiming for.
1) The module you picked has gain inside. I don't think you need a gain of 5oox more.

2) "Gain band width" Here is a graph of a 1ghz op-amp.
It works to 1ghz with a gain of 1.
It works to 100mz with a gain of 10.
It works to 10mhz with a gain of 100.
I don't think there is a single amp that will give you a gain of 500x at 300mhz.
You can use several stages of gain to get to 500x.
Probably you want "differential" to "single ended" and a gain of 1 or 2 or many be 10 at most.
10x at 300mhz = 3ghupload_2017-7-26_7-54-17.pngz amp minimum.
 
I don't think there is a single amp that will give you a gain of 500x at 300mhz.
You can use several stages of gain to get to 500x.
Probably you want "differential" to "single ended" and a gain of 1 or 2 or many be 10 at most.
10x at 300mhz = 3ghView attachment 107258z amp minimum.
Thanks for your reply Ron,
I am pretty sure I have to end up using multiple stages of gain if I want to achieve 50dB. But since I am not that familiar with differential amps, thought I would just put my specs out so that knowledgeable people like you can give your suggestions.
 

ronsimpson

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Nice, so a gain of 10 gives you 2V.
Is that single ended? Using a scope?
What is the next stage? ADC??
 
Nice, so a gain of 10 gives you 2V.
Is that single ended? Using a scope?
What is the next stage? ADC??
I think I gave you the wrong number as +/-200mV, I did some calculations today for a real-world situation and the max we can get is about +/-12mV output signal from the module.

Here is what I am planning on doing, using the differential output from the module, convert into SE signal while doing about Gain of 2 to 5 within this stage and then use multiple stages of op-amps to amplify the signal to 1V max. For amplifying SE signal, I am thinking of using two MAX4305 followed by a MAX4105 and MAX4101 (as buffer) all in series.

Any ideas or suggestions?
 
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