3. Circuits à transistors bipolaires

n
E
B
C
n
p
e
C
E
BB
C
E
B
E
C

n
UBE
UCE
IB
IC
npn
-UBE
-UCE
-IB
-IC
pnp
B
C
E
B
C
E
IE=IB+IC
IB=ISB eUBE /VT
VT
kT q
VT=kT
q'26 @ T= 300
ISB BE
ICIB
IC(IB) = β IB
β
ICUBE
IC(UBE) = (βISB )eUBE /VT=ISeUBE /VT

0 0.2 0.4 0.6 0.8
0
10
20
30
40
50
60
70
80
90
100
UBE [V]
IB [µA]
IB( UBE )
0 2 4 6 8 10
0
5
10
15
20
25
30
UCE [V]
IC [mA]
IC( UCE ), IB = param
IB = 20µA
IB = 40µA
IB = 60µA
IB = 80µA
IB = 100µA
0 0.2 0.4 0.6 0.8
0
10
20
30
40
50
60
70
80
90
100
UBE [V]
IB [µA]
IB( UBE )
0 2 4 6 8 10
0
5
10
15
20
25
30
IB = 20µA
IB = 40µA
IB = 60µA
IB = 80µA
IB = 100µA
UCE [V]
IC [mA]
IC( UCE ), IB = param
ICUCE
IC(UCE ) = IC(IB)1 + UCE
VA

VA
IE=IC+IB= (β+ 1) IB
β+ 1 'β⇒IE'IC
UBE UCE
IBIC
UBE UCE
IBIC = βIB
Vj
BE
UBE =Vj'0.6
CE
IC=β IB
VBB

VBB
RB
RE
RC
VCC
UC
UE
IE
IC
IB
0< IC< IC,max =VCC
RC+RE
UCE
VCC > UCE >0
ICUCE
IC= 0 UCE =VCC
UCE = 0 IC'IC,max
0< IC< IC,max 0< UCE < VCC
IC
VBB
Vj
UCE
VBB
Vj VBB,sat VBB,sat
VCC
RC +RE
VCC
bloqué actif saturé bloqué actif saturé