Im trying to hook up a pressure sensor that outputs voltages in the 20-250millivolt range. Ive done a little research and i think i need a non-inverting amplifier but im not entirely sure what kind of op-amp i should use. would something like this work?
Im gonna need a gain of 15.
Any input would be great.
Yes you should be able to do it with this. Why not use an inverting amplifier? It has an easier to calculate gain.
I guess im not sure what the difference is. I need it to go into the ADC of the arduino. Will in inverting amplifier give a negative voltage?
nm i think that was just a stupid assumption on my part. it looks like it just goes through the negative side on the op-amp?
The output of the op-amp will always be between the power rails of the amplifier. Power it from 5V and it will stay within limits. With an inverting amplifier as the input goes up the output goes down. With the non inverting as the input goes up the output goes up.
It doesn’t matter what you use as you can always reverse anything in the software if you need to.
No, an LM324 won't work. It is not "rail-to-rail" so its outputs probably won't go much below 2V or above 3V. Op-amps like the TLV2371 are much better for sensor interfacing with single supplies. Something like this:
Will I need a special op-amp for a differential amplifier? I didn't realize my pressure sensor outputs a reference pressure and the measured pressure, so i need to take the difference of them and then amplify.
No, the same op-amp should do. This circuit should work unless the pressure sensor outputs really can't source any current at all.
That looks like exactly what I need. Are those values of resistors for a gain of 15?
The gain will be 16. It's 1+(15k/1k). Adjust accordingly!