Chapter 7: Optical Receivers

Example 7.1,Page number 203

In [20]:
import math

#given

Trec=54;            #in ns
Ttrans=40.0;          #in ns
Pwd=(Trec-Ttrans)/Ttrans*100;

print"PWD=",Pwd,"percent";

PWD= 35.0 percent

Example 7.2,Page number 214

In [23]:
import math

#given

#Vc=Vdin-Vdinq
Vc=5;                #in mV  Vdin-Vdinq=Vc
Irset =1.8*10**-3*(Vc*10**-3);     #in A
print"Irset",Irset*10**6,"microA";
Vs=1.5;              #Voltage at signal level below Vcc in V
Radj=Vs/Irset;                     #in Ohm
print"Radj",round(Radj*10**-3,4),"kohm";

Irset 9.0 microA
Radj 166.6667 kohm

Example 7.3,Page number 223

In [24]:
import math

#given

Rl=50;      #in Ohm
Ro=100;     #in Ohm
Vos=450;            #in mV
Vref=(Rl+Ro)/Rl*Vos/2;

print"Vref= ",Vref,"mV";

Vee=3.3;            #in V
R1=500;             #in Ohm
R2=16000.0;         #in Ohm

#Rref=(Vee/Vref/10**3-1)*R1/(1-(R1/R2*(Vee/Vref/10**3-1)))
Rref=(((Vee/Vref)/(10**-3)-1)*R1)/((1-(R1/R2)*((Vee/Vref)/(10**-3)-1)));
print"Rref= ",round(Rref,4),"ohm";
print"Approx. Rref= ",round(Rref*10**-3,4),"kohm";

Vref=  675 mV
Rref=  2213.4387 ohm
Approx. Rref=  2.2134 kohm