AN60319 - Instrumentation amplifier - Design procedure for EEG signal acquisition

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Anonymous
Not applicable


Dear
I am trying to implement Instrumentation Amplifier using PSoC 5LP
I am referring the Application Note AN60319
According to the circuit given in the document i can acquire only one signal(One channel;For Example: Channel Fp1)
I am looking to acquire EEG signal from two channels Fp1 & Fp2 (According to 10-20 system)​

What design(PGA,Opamp) should i use in PSoC to implement my requirement.
Thanks in advance.

TIA, Karthik
​​
 

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1 Solution
MarkH_61
Employee
Employee
25 likes received 50 replies posted 25 replies posted

Karthik,

   

If you are going to feed the signal into the ADC anyway, you are better off to use the two opamp method and measure it differentially anyway.  Also, you can mux the inputs of the opamps so you can measure two or more differential channels.

   

 

   

Mark

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Bob_Marlowe
Level 10
Level 10
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Welcome in the forum, Karthik!

   

Sadly the PSoC5 has got only 4 OpAmps which will be short of 1 OpAmp when using the 3-OpAmp instrumentation amplifier.

   

So I would suggest you to use 2 external IAs which usually have got a better characteristic than the PSoC internal.

   

 

   

Bob

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Anonymous
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Fine Bob, then, can i use "Two Opamp Topology" to acquire signals from 2 channels ?

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Signal quality depends on your gain. most common error made in this context is:

   

All signals have to be in the range >= GND and <= VDDA. You might need a level-shifter (R-ladder) for the inputs.

   

 

   

Bob

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MarkH_61
Employee
Employee
25 likes received 50 replies posted 25 replies posted

Karthik,

   

If you are going to feed the signal into the ADC anyway, you are better off to use the two opamp method and measure it differentially anyway.  Also, you can mux the inputs of the opamps so you can measure two or more differential channels.

   

 

   

Mark

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PhNi_2262576
Level 1
Level 1
First like given

I am trying to build a EEG amp system. I used op amps a SDK kits and I am not getting anywhere. Does anyone have a completed project I plagiarize? I am having serious ground problems.

Thank You,

Philip Nielsen

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Anonymous
Not applicable

I tried as well. However after wasting 3~4 months, I started with OpenBCI project for evaluation.

There are some very interesting solutions available there which might be of interest to you. You may want to start from there and come up with something of your own later.

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In the beginning, you can use ready-made cheap solutions.

For Example  Ad8232

The main issue is the software((

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