Transistor Amplifiers and Switches
description
Transcript of Transistor Amplifiers and Switches
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill1
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
10Transistor Amplifiers and Switches
C H A P T E RC H A P T E R
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill2
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.2 Graphical interpretation of h parameters
IB ( A)
VBEVBE (V)
VBEQ
0
QIBQIB
VCE = VCEQIB ( A)
VBE
VBE (V)VBEQ
0
QIBQ
VCEQ
IC (mA)
VCE (V)0
QICQIC
V CEQ
IBQ
IC (mA)
VCE
(V)0
Q
ICQ
VCE
VCEQ
I BQ
IC
VCE
(a) Interpretation of h ie (b) Interpretation of h re
(c) Interpretation of h fe
(d) Interpretation of hoe
IB
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill3
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.3 h-parameter small-signal model for BJT
h re V CE
1h oe
B
C
E
C
E
B
IB
+
––
+ V CE
h fe I B
h ie
VBE
+ –
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill4
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.7 The BJT common-emitter amplifier
C
E
R S
R L
R E
ro
r i
CB
R 1CC
CE R 2
B
V CC
+
–
v out ( t)
R C
v S ( t )+~–
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill5
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.9 Effect of coupling capacitors on DC and AC current paths
C
E
R S
R L
R E
C C
C C
C E R 2
B
V CC
+
–
v out ( t )
DC current
AC current
R C
v S ( t )+~–
R 1
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill6
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.10 DC and AC circuits for the common-emitter amplifier
R 1
R 2
R C
R E
V CC
(a) DC circuit
R 1 || R 2v S ( t )
R C
(b) AC circuit
R L
+_~
R S
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill7
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.11 DC bias circuit for the common-emitter amplifier
B
C
E
R B
V CCR E
V BB
ICQ
I BQ
V CEQ
_
+
R C
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill8
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.24 Typical common-drain and common-source MOSFET amplifiers
+_~
V DD
R 1
D
v ( t )
R S
G SCR
R 2
R L
(b) Common-source amplifier
C S
CR D
+_~
V DD
R 1
D
v ( t )
R S
G S
C
C
R
R 2
R L
(a) Common-drain amplifier
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill9
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.27 MOSFET small-signal model
D
+
–VGS
gm VGS = ID
MOSFET small signal model
S
G
MOSFET circuit symbol
D
S
G
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill10
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.28 DC circuit for the common-source amplifier
R1 G
V GSQ
+
–
R D
R2
D
S
RSVDD
VDSQ
+
–
VDD
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill11
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.29 AC circuit for the common-source MOSFET amplifier
+_~
gm VGS
VGSR1 R2
D
v(t)
G
S
RRD RL
+
–
ID
vL(t)
+
–
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill12
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.30 MOSFET source follower and DC circuit
+~
V DD
R 1 D
v ( t )R S
GS
C
C
R
R 2v out
Source follower
R G = R 1 R 2
+
–
V GG = R 2R 1 + R 2
V DD
V GG V GSQ
V DSQ V DD
I D
R S
R G +
–+ –
DC circuit
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill13
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.31 AC equivalent circuit for the MOSFET source follower
+_~
G
V GS
R G
g m V GS
vout
+
–
S
D+
–
R S
v in
© The McGraw-Hill Companies, Inc. 2000© The McGraw-Hill Companies, Inc. 2000McGraw-HillMcGraw-Hill14
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGPRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERINGTHIRD EDITION
G I O R G I O R I Z Z O N IG I O R G I O R I Z Z O N I
Figure 10.50 MOSFET switching characteristic
v in
v out
VDD
MOSFET inverter
Switching characteristic
0 1 2 3 4 5
V DD = 5 V
VDD
R D
4 VB
– 3 V
2 V1 V
V GS = 5 Vi D
v DS (V)
1R D
A
R D