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//Example 8.3
clear;
clc;
R1=30*10^3;
R2=R1;
Cext=3*10^(-12);
GBP=20*10^6;
Cd=7*10^(-12);
Cc=12*10^(-12);
Cn=Cext+Cd+(Cc/2);
Rp=(R1*R2)/(R1+R2);
Cf1=0;
fz1=1/(2*%pi*Rp*(Cn+Cf1));
ft=20*10^6;
Q=sqrt((ft)/(2*fz1));
pm=(180/%pi)*acos((sqrt(1+(1/(4*Q^4))))-(1/(2*Q^2)));
Cf2=(R1/R2)*Cn;
fp=1/(2*%pi*R2*Cf2);
x=poly(0,'f');
A=-1/[(1+(%i*(x/fp)))*(1+(%i*(x/(0.5*ft))))];
printf("(a) Phase Margin with Cf absent=%.1f degrees",pm);
printf("\n(b) Cf for PM=90 degrees=%.2f pF",Cf2*10^12);
printf("\n(c) A(jf)=");
disp(A);
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