I don't know why I cannot operate Op-Amps! this is my second circuit and I'm trying to make a non-inverting amplifier by an OP07CP. This is my circuit + an example of measured values:
simulate this circuit – Schematic created using CircuitLab
And when I applied 0v to the +input, I got -5.47v in the output. and again for 17.9mv, I got 1.78v. when I change the supply to 0-5v, I just get an amount around 4.5v or 1.5v. I'm harassed! I expected to get 3153.969mv in the output when I applied 9.1mv but as you can see, I just got -1.15!(when supply is -12 – +12). Why doesn't it work correctly? Can I operate this Op-Amp with 0-3.3v or 0-5v supply? how?
Best Answer
Your schematic is wrong. V2 should either be +11.75V or you should flip it.
The circuit (with +/-12V-ish supplies) should work. However, you've got an offset pot- it can adjust the input offset to +/-4mV typically. If you crank it all the way down, the input can appear to be 9mV - 4mV = 5mV. Nominal gain is about 350, so this still appears to be off. You might want to parallel R2 with a small capacitor (10nF ceramic, for example) in case the op-amp is oscillating (if you have an oscilloscope, look at the output directly). Leave out the offset pot to begin with- even the cheap version is within 150uV Vos without the pot. Bypass the supplies too, near the op-amp.
The OP-07 is an ancient 'precision' op-amp with a distinguished and storied past, however it's not a rail-to-rail input or output or even a single supply op-amp. It is possible to run it from +/-5V (with some care) but not (reliably) from 0/5V.