G = (R1+R2)/R1 = 11
According to the datasheet, that op-amp has a 1mV typical input offset voltage.
Try a larger input voltage e.g. 20mV or 200mV.
OpAmp Gain trouble
Dec 01, 2005
3 Replies
I am using the below schematic for a OpAmp TLC272CP. According to the formula of G = (R1/R2) the gain on this circuit should only be a matter of 11. however as you can see below it's closer to 15/16. I'm wondering what could cause this anomoly. I have put the circuit below(sorry for the Ascii) and what i put into the + of the opamp and what i got as output.
Thanks
base=2.0mv output=33.4mV
+9V +9V | (+). |
100k pot
answered in s.e.d.
Such questions should be cross-posted to avoid stupid duplication and waste of time.
Graham
Get rid of R3.
Also, try making a few measurements, and plotting the output vs input for input = .5, .4, .3, .2, .1... That might give you a clue as to what is happening.
Regards,
Bob Monsen
Music is the pleasure the human soul experiences from counting without
being aware that it is counting.
- Gottfried Leibniz
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required