updated the code

1 files changed, 29 insertions, 28 deletions

diff --git a/68/CH5/EX5.18/ex18.sce b/68/CH5/EX5.18/ex18.sce
index d556d5680..bf511e347 100755
--- a/68/CH5/EX5.18/ex18.sce
+++ b/68/CH5/EX5.18/ex18.sce
@@ -1,29 +1,30 @@
-//Example 5.18 : Midband gain and 3dB frequency

-// Transistor is biased at I_C=1mA

-V_CC=10; // (V)

-V_EE=10; // (V)

-I=0.001; // (A)

-R_B=100000; // (ohm)

-R_C=8000; // (ohm)

-R_sig=5000; //(ohm)

-R_L=5000; // (ohm)

-B=100; // beta value

-V_A=100; // (V)

-C_u=1*10^-12; // (F)

-f_T=800*10^6; // (Hz)

-I_C=0.001; // (A)

-r_x=50; // (ohm)

-// Values of hybrid pi model parameters

-g_m=I_C/V_T;

-r_pi=B/g_m;

-r_o=V_A/I_C;

-w_T=2*%pi*f_T;

-CpiplusCu=g_m/w_T; // C_u+C_pi

-C_pi=CpiplusCu-C_u;

-R_l=r_o*R_C*R_L/(r_o*R_C+R_C*R_L+R_L*r_o) // R_l=R_L'

-A_M=R_B*r_pi*g_m*R_l/((R_B+R_sig)*(r_pi+r_x+(R_B*R_sig/(R_B+R_sig))));

-disp(A_M,"Midband gain (V/V)")

-R_seff=(r_pi*(r_x+R_B*R_sig/(R_B+R_sig)))/(r_pi+r_x+R_B*R_sig/(R_B+R_sig)); // Effective source resistance R_seff=R'_sig

-C_in=C_pi+C_u*(1+R_l*g_m);

-f_H=1/(2*%pi*C_in*R_seff);

+//Example 5.18 : Midband gain and 3dB frequency
+// Transistor is biased at I_C=1mA
+V_CC=10; // (V)
+V_T=25*10^-3;
+V_EE=10; // (V)
+I=0.001; // (A)
+R_B=100000; // (ohm)
+R_C=8000; // (ohm)
+R_sig=5000; //(ohm)
+R_L=5000; // (ohm)
+B=100; // beta value
+V_A=100; // (V)
+C_u=1*10^-12; // (F)
+f_T=800*10^6; // (Hz)
+I_C=0.001; // (A)
+r_x=50; // (ohm)
+// Values of hybrid pi model parameters
+g_m=I_C/V_T;
+r_pi=B/g_m;
+r_o=V_A/I_C;
+w_T=2*%pi*f_T;
+CpiplusCu=g_m/w_T; // C_u+C_pi
+C_pi=CpiplusCu-C_u;
+R_l=r_o*R_C*R_L/(r_o*R_C+R_C*R_L+R_L*r_o) // R_l=R_L'
+A_M=R_B*r_pi*g_m*R_l/((R_B+R_sig)*(r_pi+r_x+(R_B*R_sig/(R_B+R_sig))));
+disp(A_M,"Midband gain (V/V)")
+R_seff=(r_pi*(r_x+R_B*R_sig/(R_B+R_sig)))/(r_pi+r_x+R_B*R_sig/(R_B+R_sig)); // Effective source resistance R_seff=R'_sig
+C_in=C_pi+C_u*(1+R_l*g_m);
+f_H=1/(2*%pi*C_in*R_seff);
 disp(f_H,"3dB frequency (Hz)")
\ No newline at end of file