How do I build a differential amplifier in PSoC 5?

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Anonymous
Not applicable

 Hi all,

   

How to build a differential amplifier with the gain of 10 in PSOC 5 and connect it to a Delta Sigma  ADC? That means that the analog signal firstly goes into a differential amplifier with the gain of 10 and then is fed into a Delta Sigma  ADC.

   

In datasheet, Delta Sigma  ADCs have differential input option. The maximum input buffer gain is 8. Does it mean that there is a a differential amplifier front-end and the maximum gain is 8? 

   

Thank you very much!!

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

You may use an PSoC5 internal opamp and connecting 4 resistors to get your desired differential amplifier with gain 10.

   

 

   

Bob

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

Some thoughs -

   

 

   

1) The input buffer is differential, and you can get a G = 8 out of it.

   

2) The input buffer z is fairly low, check datasheet, so you can do

   

design calculaltions for CMRR.

   

3) Design needs to start with desired resolution and accuracy, so you

   

can do a signal path analysis. If you are at higher resolution take

   

a look at the datasheet for CMRR vs G. In advisable to use a single

   

OpAmp with 4 Rs for a diff map. You will have limited CMRR. Think

   

about using a single chip, 3 amp IA, they are factory trimmed, for T as

   

well,can approach 22 - 24 bit performance,

   

 

   

Regards, Dana,

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

If you want a lot f ref material I can email you, send me your address

   

and I will forward.

   

 

   

Regards, Dana.

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Anonymous
Not applicable

 Thank you guys!!! You are very helpful! I'm a beginner of PSoC but it seems amazing. I've have some basic idea of that with your help.  My mail address is mamengxuan1990@gmail.com. I'll really appreciate if you could send me more reference.

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

I have forwarded the ref material.

   

 

   

Regards, Dana.

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