Chapter 13: Networks

Example 13.1,Page number 568

In [2]:
import math

#given

Vcc=5;              #in V
Vf=1.5;             #in V
If=60;              #in mA
B=3.97;
N=3;
R9=(Vcc-Vf)*(B+1)/If/10**-3;
print"R9 =",round(R9,4),"ohm";
R7=R9/2/B-3/N;
print"R7 =",round(R7,4),"ohm";
R8=R9/2/B;
print"R8 =",round(R8,4),"ohm";
C4=2*10**-9/R8;
print"C4 =",round(C4*10**12,4),"pF";

R9 = 289.9167 ohm
R7 = 35.5134 ohm
R8 = 36.5134 ohm
C4 = 54.7744 pF

Example 13.2,Page number 569

In [5]:
import math

#given

Vu3=1.24;           #in V
Vbeq3=0.7;          #in V
Vbeq4=0.7;          #in V
R5=17.5;            #in Ohm
R6=17.5;            #in Ohm
Voh=5;              #in V
Vol=0;              #in V

If=(Vu3-Vbeq3)/R5+(Vu3-Vbeq4)/R6;
print"If=",round(If*1000,4),"mA";

R3=(Voh-Vol)/If;
print"R3=",round(R3,4),"ohm";

C4=2*10**-9/R3;
print"C4=",round(C4*10**12,4),"pF";

If= 61.7143 mA
R3= 81.0185 ohm
C4= 24.6857 pF

Example 13.2,Page number 581

In [7]:
##"Page number 581 again  Example 13-2 (numbering mistake)";
import math

#given

Er=4.9;
h=5;                 #in mils
w=10;                #in mils
t=0.5;               #in mils

Z=60.0/math.sqrt(0.475*Er+0.67)*log(4*h/0.67/(0.8*w+t));
print"Z =",round(Z,4),"ohm";

tpd=1.017*sqrt(0.475*Er+0.67);
print"tpd =",round(tpd,4),"ns/ft";

Tpd=tpd*1000/12;           #converted into ps/in
print"tpd =",round(Tpd,4),"ps/in";

Co=Tpd/Z;
print"Co =",round(Co,4),"pF/in";

Page number 581 again  Example 13-2 (numbering mistake)
Z = 43.5322 ohm
tpd = 1.7608 ns/ft
tpd = 146.7301 ps/in
Co = 3.3706 pF/in

Example 13.3,Page number 583

In [10]:
import math

#given

Er=4.7;
b=10;                #in mils
w=4;                 #in mils
t=0.5;               #in mils

Z=60/math.sqrt(Er)*log(4*b/0.67/math.pi/(0.8*w+t));
print" Z =",round(Z,4),"ohm";

tpd=1.017*sqrt(Er);
print" tpd =",round(tpd,4),"ns/ft";

Tpd=tpd*1000/12;           #converted into ps/in
print" Also,tpd =",round(Tpd,4),"ps/in";

 Z = 45.286 ohm
 tpd = 2.2048 ns/ft
 Also,tpd = 183.7336 ps/in