I would like to make precision amplifier circuit for differnetial pressure sensor. I make a circuit roughly. Initially the adjustable offset is made like
this: First, I connect scope at AD8221(U1) output, then adjust VR4(trimmer) to shift U1 output to zero(0 V). then adjust gain to needed range. input range is -10V ~ +10V, differential input range is -500mv ~ 500mv.
But, the attached circuit does not operate acurately. When I change input value. U1/REF pin value is changing and output value is also inaccurate.
Good members would like to be joined for help to complete this project.
Thanks.
SunSung Hwang
this: First, I connect scope at AD8221(U1) output, then adjust VR4(trimmer) to shift U1 output to zero(0 V). then adjust gain to needed range. input range is -10V ~ +10V, differential input range is -500mv ~ 500mv.
But, the attached circuit does not operate acurately. When I change input value. U1/REF pin value is changing and output value is also inaccurate.
Good members would like to be joined for help to complete this project.
Thanks.
SunSung Hwang
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