what's the difference between dynamic range and SNR?

SNR=ratio between signal and noise(two are different )...Dynamic range is to relate a single quantity either signal or noise...DR= Maxamplitude(signal or noise)/Minamplitude(signal or noise)..no units for DR

thanks!
Does't is mean if the minamplitude of signal have the same magnitude with noise,then DR=SNR?

yes both will be equal if noise voltage attains minimum value of signal...
also high Dr and SNR are always desired...

For a perfect linear system DR and SNR are equivalent.

The proper definiton of DR is the ration of max/min signal amplitude at which a min SNR is guaranteed.

They clearly differ for non-linear systems.

nathan