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offset problem of AD8629 OPAMP

Question asked by Kaos on Dec 18, 2015
Latest reply on Nov 29, 2016 by BCard

Dear Sir/Madam,

 

Our customer have met one trouble as following.

(This discuss came from another sled cause my miss understood)

 

On my enclosed schematic Fig-1.pdf,

step-1 power off and keep waiting around 30 sec

step-2 power on

step-3 around 90msec offset voltage appear at out-1 pin

step-4 power off and on but the 90mV offset is not cleared

 

Also refer to my enclosed time chart "tme chart when power off and on.pdf".

note

*1 ; 30sec is not certainly.

*3 ; in some cases, it return to expected value

After once this trouble happen, out-2 is up and dowm on offset voltage 900mV(x10 gained value)

 

When we work with above action, does your AD8629 do such a motion?or not.

If he replace the thermopile(TP) to fixed resister 175kohm, then the result was same.

 

Please advice us before your holiday!!

 

Thank you in advance Kaos

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