
Ampliers: Basic BJT Congurations
401
Wih MATLAB
®
we can graph A
iBJT
versus h
fe
and h
oe
(Figure 11.36):
% AiBJTCE vs. hfe and hoe
clear clf
Rc = 4000; Rl = 10000;
hfe = [50:10:250]; hoe = [0:0.0001:0.001];
[X,Y] = meshgrid(hfe,hoe);
Z = X./(1+Y.*((Rc.*Rl)./(Rc+Rl)));
mesh(X,Y,Z)
xlabel('hfe'); ylabel('hoe'); zlabel('AiBJTCE');
Similarly, we can graph A
iBJT
versus R
C
and R
L
(Figure 11.37):
% AiBJTCE vs. Rc and Rl
hfe = 200; hoe = 0.001;
Rc = [10:100:10000]; Rl = [10:100:10000];
[X,Y] = meshgrid(Rc,Rl);
Z = hfe./(1+hoe.*((X.*Y)./(X+Y)));
mesh(X,Y,Z)
axis([0 10000 0 10000 50 200])
xlabel('Rc'); ylabel('Rl'); zlabel('AiBJTCE');
250
200
150
iBJTCE
100
50
0
1
0.8
0.6
0.4