PPT: BJT - Biasing & Stabilization | Analog Circuits - Electronics and Communication Engineering (ECE) PDF Download

 Page 1


BJT BIASING, STABILIZATION 
AND
H-PARAMETERS
Page 2


BJT BIASING, STABILIZATION 
AND
H-PARAMETERS
INTRODUCTION
• BJT -- Bipolar Junction Transistor
• Three terminals-Base, Emitter, Collector
• Type —NPN and PNP
• T wo Junctions – (a)Emitter-Base Junction
(b) Collector-Base Junction
• Transistor = Transfer+ Resistor
• Capability of transferring signal current from low resistance circuit to high
resistance circuit
2
Page 3


BJT BIASING, STABILIZATION 
AND
H-PARAMETERS
INTRODUCTION
• BJT -- Bipolar Junction Transistor
• Three terminals-Base, Emitter, Collector
• Type —NPN and PNP
• T wo Junctions – (a)Emitter-Base Junction
(b) Collector-Base Junction
• Transistor = Transfer+ Resistor
• Capability of transferring signal current from low resistance circuit to high
resistance circuit
2
• Application —BJT as an amplifier and switch
• Base is located at the middle and more thin from 
the level of collector and emitter
• The emitter and collector terminals are made of 
the same type of semiconductor material, while 
the base of the other type of material
3
Figure 2  (a) Transistor Types  (b) Symbol of Transistor
Figure 1 Cross sectional view of BJT
Page 4


BJT BIASING, STABILIZATION 
AND
H-PARAMETERS
INTRODUCTION
• BJT -- Bipolar Junction Transistor
• Three terminals-Base, Emitter, Collector
• Type —NPN and PNP
• T wo Junctions – (a)Emitter-Base Junction
(b) Collector-Base Junction
• Transistor = Transfer+ Resistor
• Capability of transferring signal current from low resistance circuit to high
resistance circuit
2
• Application —BJT as an amplifier and switch
• Base is located at the middle and more thin from 
the level of collector and emitter
• The emitter and collector terminals are made of 
the same type of semiconductor material, while 
the base of the other type of material
3
Figure 2  (a) Transistor Types  (b) Symbol of Transistor
Figure 1 Cross sectional view of BJT
Transistor currents 
•The arrow is always drawn
  on the emitter
•The arrow always point 
  toward the n-type
•The arrow indicates the 
  direction of the emitter      
  current:
pnp:E ? B
npn: B ? E
Figure 3 Transistor Currents in PNP and NPN Transisitor
I
E
 = I
C
 + I
B
4
Page 5


BJT BIASING, STABILIZATION 
AND
H-PARAMETERS
INTRODUCTION
• BJT -- Bipolar Junction Transistor
• Three terminals-Base, Emitter, Collector
• Type —NPN and PNP
• T wo Junctions – (a)Emitter-Base Junction
(b) Collector-Base Junction
• Transistor = Transfer+ Resistor
• Capability of transferring signal current from low resistance circuit to high
resistance circuit
2
• Application —BJT as an amplifier and switch
• Base is located at the middle and more thin from 
the level of collector and emitter
• The emitter and collector terminals are made of 
the same type of semiconductor material, while 
the base of the other type of material
3
Figure 2  (a) Transistor Types  (b) Symbol of Transistor
Figure 1 Cross sectional view of BJT
Transistor currents 
•The arrow is always drawn
  on the emitter
•The arrow always point 
  toward the n-type
•The arrow indicates the 
  direction of the emitter      
  current:
pnp:E ? B
npn: B ? E
Figure 3 Transistor Currents in PNP and NPN Transisitor
I
E
 = I
C
 + I
B
4
TRANSISTOR CURRENT GAIN