matlab modeling of mosfet current mirror(req)

[ravitest]

matlab code for mosfet operation

hi, please help me, i wrote a matlab program for mosfet which shown below with result, then how can i use this code for generating of basic current mirror in matlab, please give me suggestions.




kn=1e-3; vt=1.5;
vds=0:0.5:12;
vgs=4:2:8;
m=length(vds);
n=length(vgs);
for i=1:n
for j=1:m
if vgs(i) < vt
cur(i,j)=0;
elseif vds(j) >= (vgs(i) - vt)
cur(i,j)=kn * (vgs(i) - vt)^2;
elseif vds(j) < (vgs(i) - vt)
cur(i,j)= kn*(2*(vgs(i)-vt)*vds(j) - vds(j)^2);
end
end
end
plot(vds,cur(1,,'w',vds,cur(2,,'w',vds,cur(3,,'w')
xlabel('Vds, V')
ylabel('Drain Current,A')
title('I-V Characteristics of a MOSFET')
text(6, 0.009, 'Vgs = 4 V')
text(6, 0.023, 'Vgs = 6 V')
text(6, 0.045, 'Vgs = 8 V')

 

[hmsheng]

mosfet, matlab

Given a reference current you can calculate the VGS with this equation:
cur(i,j)=kn * (vgs(i) - vt)^2; (VDS=VGS for simple current mirror)
Then, use this VGS to the mirrored MOS device, the mirrored current can be calculated.

Be sure that the mirrored MOS device should operate at linear region (VDS>VGS-Vth), or else the mirrored current is not accurate as you want.