[SOLVED] Why are high swing analog circuits less sensitive to noise?

[venugopala_0202]

I just wanted to know why analog circuits with a higher swing(amplitude) less sensitive to noise in a mixed signal environment?

 

[kripacharya]

possibly because the ratio of signal to noise becomes higher ?

 

[prestonee]

At first I thought you were asking why rail to rail topologies are less sensitive to noise, was going to ask you where you heard that. But yea I agree with krip, if you use an amp near its max signal swing the entire time, its snr is higher(closer to the max snr of that design). thats why you always design the circuit to make use of the range, no sense in having an amp with gain of 2 if the max signal gives you an output of only 25% of the available supply. In some cases you will see auto gain feedback amps, where the output of the signal is monitored and adjustments to the gain are made based on an algorithm.
-Pb