hi,

when i connect a circuit with CRO. every time i get noise on cro weather it's circuit or output pin of microcontroller. noise is very small approx. 100mV. i want to remove this noise. how to remove this noise.

 

do you get the same results when you short the probe?
What do you measure when you connect the tip of the probe to the ground of the circuit, without connecting the probe ground to anything?
How are your circuits powered? Do you get the same noise when measuring a battery powered circuit?
What is the frequency range of your scope and what freqency is the noise?

 

First question should be what is the make and model of the oscilloscope?