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 mate New Member Offline Posts: 2 Question about Offset-Simulation of comparators Nov 23rd, 2010, 11:45pm   Hi all,i designed a latched comparator and performed a simulation like the one described in the paper 'A Methology for the Offset-simulation of comparators' http://www.designers-guide.org/Analysis/comparator.pdf from this website.No I have some questions:1. During the post-analysis in Matlab (code is at the bottom of this post) one defines Code:```% select values within -2.5 .. 2.5 sigma i=find(v>-2.5 & v < 2.5) ```Why choose sigma = 2.5? At the end one defines Code:```sigma = 1/p(1) ```This should be the sigma_offset. This value changes if I use another value than 2.5 within the find function. I'm now not sure why he took 2.5 sigma.2. My result gives me a mu of 30mV and a sigma of 30mV (when calculated like described). Is this interpretation correct:My threshold is now: threshold_ideal+mu, but how do i interpret this sigma?3. Does anyone know any material/website about how get sigma and mu from the polynomial coefficients?Thanks for your help!-----complete code: Code:```% it is assumed that the simulation results are provided % in the matrix "ydata" and the array "xdata" % (1) ni/N, Figure 2 y = sum(ydata)/length(ydata); plot(xdata, y) % (2) inverse erf for rising slope only % y(1:21) is this case contains the data % for the rising slope v = sqrt(2)∗erfinv(y(1:21)∗2−1); % select values within −2.5 ... 2.5 sigma i=find(v>−2.5 & v<2.5) % fit line through selected values % Figure 5 [p,s]=polyfit(xdata(i), v(i), 1); plot(xdata(i), v(i), xdata(i), polyval(p,x(i))) % (4) compute mu and sigma sigma = 1/p(1); mu = −p(2)/p(1); ``` Back to top IP Logged
 mate New Member Offline Posts: 2 Re: Question about Offset-Simulation of comparators Reply #1 - Nov 24th, 2010, 1:57am   Hi,i just want to add some of my results.i have used Code:```i = find(v>-3 & v<3) ```the results are: μ: 2.5m σ: 25mIs that σ value (25m) now my 3σ already or do i have to multiply that one with 3 to get 3σ (which would be 75m) Back to top « Last Edit: Nov 25th, 2010, 12:07am by mate »     IP Logged