Can anybody give me a hint-----noise analysis in SAR adc?

[luantan]

noise analysis + sar adc

Everybody knows that a SAR ADC contains a DAC and a comparator.
If the comparator is required to be high speed, then it may be auto zeroed comparator
consists of several cascaed pre amplifiers and a latch.

my question is :
How the noise of the comparator should be caculated, what is the noise bandwidth?
Is the noise bandwidth just the bandwidth of the preamplifier?
or is the noise bandwidth the nyquist frequency of that ADC?
or something else....?
why?
Thank u for give me a hint, this problem make me so troublesome for a long time.
Thank u for your valueble suggestion!!!!!

 

[rag_perfect]

noise analysis

thaoa's sp simlple;
just imagine that noise is white nose;
psd is eta/2; now integrate the psd over band width uget the power valu;
power ia equal to voltage square upon resistance valu;
so if r=1; v=sqrt of power ;thatis value of noise voltage.

rag_perfect.