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I need to amplify voltages from range of -5mV/5mV to voltages of range -5V/5V. So I used circuit from the image.Amplifying circuit LF356N

I decided to check if it is working by connecting it to Arduino Uno to simulate signal and to power the amplifier. When checking the output voltage I found that it is 3.5V. After removing the signal, output voltage did not change, it was still 3.5V.

I am new to this kind of circuits and I cannot find the problem why it is not amplifying the signal but giving constant values. Any help would be appreciated.

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  • \$\begingroup\$ Your LF356 is not specified to operate with only a 5V supply. Not even close. Read the datasheet. \$\endgroup\$
    – brhans
    Commented Apr 3, 2018 at 14:37
  • \$\begingroup\$ Also note that the LF356 has a typical 3mV input offset voltage. Your circuit has a DC gain of 1000, so that would mean that, even if the supply was OK, you would have 3V at the output even with the non-inverting input connected to GND, because you'd be amplifying the offset. \$\endgroup\$
    – freejuices
    Commented Apr 3, 2018 at 14:41

1 Answer 1

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Read the datasheet before choosing an op-amp.

You are violating the recommended supply voltage range

enter image description here

and the input common-mode voltage range

enter image description here

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