CHAPTER 6 BIPOLAR JUNCTION TRANSISTOR

Example 6-1, Page 194

In [10]:
Ic=10                  #collector current(mA)
Ib=40.0/1000.0         #base current (mA)

Bdc=Ic/Ib            #Current gain

print 'Current gain Bdc =',Bdc

Current gain Bdc = 250.0

Example 6-2, Page 194

In [9]:
Bdc=175                #current gain
Ib=0.1                 #base current (mA)

Ic=Bdc*Ib            #Current gain

print 'Collector current Ic =',Ic,'mA'

Collector current Ic = 17.5 mA

Example 6-3, Page 195

In [1]:
Bdc=135.0              #current gain
Ic=2.0                 #collector current (mA)

Ib=(Ic/Bdc)*1000       #Current gain

print 'Base current Ib =',round(Ib,2),'uA'

Base current Ib = 14.81 uA

Example 6-4, Page 197

In [2]:
Vbb=2                  #base source voltage(V)
Rb=100                 #base resistor (KOhm)
Bdc=200                #current gain
Vbe=0.7                #base-emitter voltage drop(V)

Ib=((Vbb-Vbe)/Rb)*1000 #base current(uA)
Ic=Bdc*Ib/1000         #Collector current(mA)

print 'Base current Ib =',Ib,'uA'
print 'Collector current Ic =',Ic,'mA'

Base current Ib = 13.0 uA
Collector current Ic = 2.6 mA

Example 6-5, Page 201

In [3]:
VBB=10                   #Base voltage (V)
RC=2                     #Collector resistance(KOhm)
VCC=10                   #collector voltage(V)
Bdc=300                  #current gain
RB=1                     #base resistance (MOhm)
VBE=0.7                  #base-emitter voltage drop(V) 

IB=((VBB-VBE)/RB)          #base current(uA)
IC=Bdc*IB/1000             #Collector current(mA)
VCE=VCC-(IC*RC)            #Collector-emitter voltage(V)
PD=VCE*IC                  #Collector power dissipation(W)

print 'Base current IB =',IB,'uA'
print 'Collector current IC =',IC,'mA'
print 'Collector-emitter voltage VCE =',VCE,'V'
print 'Power dissipation PD = ',round(PD,2),'W'

Base current IB = 9.3 uA
Collector current IC = 2.79 mA
Collector-emitter voltage VCE = 4.42 V
Power dissipation PD =  12.33 W

Example 6-6, Page 202

In [4]:
VBB=10                   #Base voltage (V)
RC=470                   #Collector resistance(Ohm)
VCC=10                   #collector voltage(V)
Bdc=300                  #current gain
VCE=5.4535               #collector-emitter voltage shown on multisim screen 
RB=330                   #base resistance (KOhm)
VBE=0.7                  #base-emitter voltage drop 

IB=((VBB-VBE)/RB)*1000    #base current(uA)
V=VCC-VCE                 #voltage across Rc
IC=(V/RC)*1000            #Collector current(mA)
Bdc=int((IC/IB)*1000)     #Collector-emitter voltage

print 'Base current IB =',round(IB,2),'uA'
print 'voltage across Rc VRc = ',round(V,2),'V'
print 'Collector current IC =',round(IC,2),'mA'
print 'Current gain Bdc = ',Bdc

Base current IB = 28.18 uA
voltage across Rc VRc =  4.55 V
Collector current IC = 9.67 mA
Current gain Bdc =  343

Example 6-7, Page 204

In [5]:
VBB=15                   #Base voltage (V)
RC=3.6                   #Collector resistance(KOhm)
VCC=15                   #collector voltage(V)
Bdc=100                  #current gain
RB=470                   #base resistance (KOhm)
VBE=0                    #base-emitter voltage drop(V) 

IB=((VBB-VBE)/float(RB))*1000     #base current(uA)
IC=Bdc*IB/1000                    #Collector current(mA)
VCE=VCC-(IC*RC)                   #Collector-emitter voltage(V)
IE=IC+(IB/1000)                   #emitter current(mA)

print 'Base current IB =',round(IB,2),'uA'
print 'Collector current IC =',round(IC,2),'mA'
print 'Collector-emitter voltage VCE = ',round(VCE,2),'V'
print 'Emitter current IE =',round(IE,2),'mA'

Base current IB = 31.91 uA
Collector current IC = 3.19 mA
Collector-emitter voltage VCE =  3.51 V
Emitter current IE = 3.22 mA

Example 6-8, Page 205

In [6]:
VBB=15                   #Base voltage (V)
RC=3.6                   #Collector resistance(KOhm)
VCC=15                   #collector voltage(V)
Bdc=100                  #current gain
RB=470                   #base resistance (KOhm)
VBE=0.7                  #base-emitter voltage drop(V) 

IB=((VBB-VBE)/float(RB))*1000     #base current(uA)
IC=Bdc*IB/1000                    #Collector current(mA)
VCE=VCC-(IC*RC)                   #Collector-emitter voltage(V)

print 'Base current IB =',round(IB,2),'uA'
print 'Collector current IC =',round(IC,2),'mA'
print 'Collector-emitter voltage VCE = ',round(VCE,2),'V'

Base current IB = 30.43 uA
Collector current IC = 3.04 mA
Collector-emitter voltage VCE =  4.05 V

Example 6-9, Page 206

In [7]:
VBB=15                   #Base voltage (V)
RC=3.6                   #Collector resistance(KOhm)
VCC=15                   #collector voltage(V)
Bdc=100                  #current gain
RB=470                   #base resistance (KOhm)
VBE=1                    #base-emitter voltage drop(V) 

IB=((VBB-VBE)/float(RB))*1000     #base current(uA)
IC=Bdc*IB/1000                    #Collector current(mA)
VCE=VCC-(IC*RC)                   #Collector-emitter voltage(V)

print 'Base current IB =',round(IB,2),'uA'
print 'Collector current IC =',round(IC,2),'mA'
print 'Collector-emitter voltage VCE = ',round(VCE,2),'V'

Base current IB = 29.79 uA
Collector current IC = 2.98 mA
Collector-emitter voltage VCE =  4.28 V

Example 6-10, Page 206

In [8]:
VBB=5                    #Base voltage (V)
RC=3.6                   #Collector resistance(KOhm)
VCC=15                   #collector voltage(V)
Bdc=100                  #current gain
RB=470                   #base resistance (KOhm)
VBE1=0                   #base-emitter voltage drop1(V) 
VBE2=0.7                 #base-emitter voltage drop2(V)
VBE3=1                   #base-emitter voltage drop3(V)

IB1=((VBB-VBE1)/float(RB))*1000     #base current1(uA)
IC1=Bdc*IB1/1000                    #Collector current1(mA)
VCE1=VCC-(IC1*RC)                   #Collector-emitter voltage1(V)

IB2=((VBB-VBE2)/float(RB))*1000     #base current2(uA)
IC2=Bdc*IB2/1000                    #Collector current2(mA)
VCE2=VCC-(IC2*RC)                   #Collector-emitter voltage2(V)

IB3=((VBB-VBE3)/float(RB))*1000     #base current3(uA)
IC3=Bdc*IB3/1000                    #Collector current3(mA)
VCE3=VCC-(IC3*RC)                   #Collector-emitter voltage3(V)

print 'Base current IB1 =',round(IB1,2),'uA'
print 'Collector current IC1 =',round(IC1,2),'mA'
print 'Collector-emitter voltage VCE1 = ',round(VCE1,2),'V'

print 'Base current IB2 =',round(IB2,2),'uA'
print 'Collector current IC2 =',round(IC2,2),'mA'
print 'Collector-emitter voltage VCE2 = ',round(VCE2,2),'V'

print 'Base current IB3 =',round(IB3,2),'uA'
print 'Collector current IC3 =',round(IC3,2),'mA'
print 'Collector-emitter voltage VCE3 = ',round(VCE3,2),'V'

Base current IB1 = 10.64 uA
Collector current IC1 = 1.06 mA
Collector-emitter voltage VCE1 =  11.17 V
Base current IB2 = 9.15 uA
Collector current IC2 = 0.91 mA
Collector-emitter voltage VCE2 =  11.71 V
Base current IB3 = 8.51 uA
Collector current IC3 = 0.85 mA
Collector-emitter voltage VCE3 =  11.94 V

Example 6-11, Page 211

In [9]:
VCE=10                    #Collector-emitter voltage(V)
IC=20                     #Collector current(mA)
T=25                      #Ambient temperature(deg C)
                    
PD = VCE*IC               #Power dissipation(mW)

print 'Power dissipation PD = ',PD,'mW'
print 'for 25 deg C, power rating is 625 mW So, transistor is well within power rating.'

Power dissipation PD =  200 mW
for 25 deg C, power rating is 625 mW So, transistor is well within power rating.

Example 6-12, Page 212

In [10]:
T1=100                    #Ambient temperature(deg C)
T2=25                     #Reference temperature(deg C)
mf=5                      #Multiply factor(mW/deg C)   
Pr=625                    #power rating(mW)

Td=T1-T2                  #Temperature difference(deg C)
Pd=mf*Td                  #Difference in power(mW)
PDmax=Pr-Pd               #Maximum power dissipation(mW)

print 'Maximum Power dissipation PDmax = ',PDmax,'mW'
print 'for 25 deg C, power rating is 625 mW So, transistor is yet within power rating.'

Maximum Power dissipation PDmax =  250 mW
for 25 deg C, power rating is 625 mW So, transistor is yet within power rating.
In [ ]: