Implementing Differential amplifier on PSoC 1

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Anonymous
Not applicable

 Hi,

   

    I am trying to implement a differential amplifier to convert an input signal range of 1-5V to 0-4 V. I tried it using 2 back to back PGAs with first stage (Gain=1,ref Vss) providing 1V ref to second stage(Gain=1) to which input signal of 1-5 volts is applied.But this did not work as expected.

   

    Has anyone implemented it before?Please help me out.

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3 Replies
Anonymous
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        Hi   
What is "1-5V to 0-4V" ?   
Be explain more in detail.   
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ETRO_SSN583
Level 9
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You cannot implement an effective diffamp using PGAs because their

   

gain accuracy tracking is so poor your CMRR will suffer, the whole point

   

of using a diffamp is CMR.

   

 

   

You are not using INSAMP module in the component catalog ?

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
Level 9
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Here is an analysis supporting prior post in thread -

   

 

   

http://www.cypress.com/?app=forum&id=2492&rID=82151

   

 

   

Regards, Dana.

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