Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Op-Amp vs instrumentation amplifier in signal conditioning application

Status
Not open for further replies.
Ahmad Tarek

Ahmad Tarek

Electrical
Dec 29, 2021
2
Hello everyone,
I have a questions and i hope someone can help me with,

I am currently working on a medical device comprising 8 analog sensors, i use low pass active filter as an analog signal conditioning.
Some sensors require output amplification as their output is within the range(0..100mV).
I am currently using LM324 for active filter and amplification application, which is very cost efficient, however, i have been advised to use instrumentation amplifier instead,
The problem with the instrumentation amplifier is that they are really expensive,

Can someone please advise and explain which type of amplifier should i use and Why?

Thanks in advance,
Ahmad Tarek
 
Replies continue below

Recommended for you

Sort by date Sort by votes
I suggest you ask the person who asked you to change why they did so. Also, presumably, you have some sort of spec. Does the current system meet this spec?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
Upvote 0 Downvote
Untitled_tmtkhp.png

You can always make an instrumentation amp (to a degree) out of two regular ones, if the cost difference is significant enough...

Dan - Owner
Footwell%20Animation%20Tiny.gif
 
Upvote 0 Downvote
If the sensors are strain gauges or unconditioned pressure sensors then a instrumentation amplifier is the way to go. These require differential input amplification also.

But if these 'sensors' have internal active circuits and a single-ended output then a regular op-amp may be the better way to go.

I've designed many sensor and control circuits for -40 to 85C using no more than LM2904 opamps (LM324 family). Not hard to do if you know your signal source and you arrange the circuit so the input bias current/offset voltage will cancel in the circuit. I've also designed circuits where I never considered anything other than instrumentation op amp from the start.

 
Upvote 0 Downvote
Thank you everyone for your answers,
I am attaching the circuits where i am using the op-amp,
Filtering circuit
Filtering_circuit_qfmdex.png


Amplification circuit
amplification_circuit_xa1jch.png


Thanks in advance
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

SaraXelon
  • Locked
  • Question
Dual 4-20mA signal but need a single 4-20mA signal output
Replies
7
Views
7K
SaraXelon
SaraXelon
ATpeter
  • Locked
  • Question
Instrumentation - set point / scale on 4-20mA
Replies
2
Views
638
salmanshu322
salmanshu322
rucka24
  • Locked
  • Question
What algorithms can provide accurate displacement data with MAG data for short-term applications?
Replies
1
Views
6K
IRstuff
IRstuff
BOUFEK
  • Locked
  • Question
Why can't i get a mili Amp mA value from this leveltransmitter
Replies
7
Views
825
BOUFEK
BOUFEK
Caleb Rhyne
  • Locked
  • Question
Difference Between Lock-In Amplifiers and other Coherence methods
Replies
1
Views
221
zappedagain
zappedagain

Part and Inventory Search

Sponsor

Back
Top Bottom