I'm looking for a simple analog circuit to keep my output steady when input varies slightly, it constantly varies a tenth of a volt back and forth!
0-1 volt circuit ( output voltage needs to mirror input voltage) Problem is a tenth of a volt or so causes my LED readout to vary too much and I need it to be stable. 5 volt regulated supply is available for supply voltage. Can have a 1-2 second buffer. This is for a temperature Display readout! Thankyou for your time!
Are you trying to say that you need a unity-gain low-pass filter with a cutoff frequency of ~0.2Hz?
Note the sim. The output of the filter settles to near the average value of the input waveform. The filter can be more aggressive with more poles, or by moving the cutoff frequency lower. Depends on what your input looks like.