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ELCT 1003:High Speed Electronic Circuit
Lecture 8: Compensation of some Operational-Amplifier for High-Frequency Applications
(continued)
Dr. Mohamed Abd El Ghany, Department of Electronics and Electrical Engineering
Mohamed.abdel-ghany@guc.edu.eg
Frequency Response of inverting
Amplifier
2Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
)(
VVAVo
ELCT 1003: High Speed
Electronic Circuits
Vin
Vo
R βR
0
V
oinVVV
1
1
1
oin
o VVA
V
1
1
10
inoVV
A 11
11
A
V
V
in
o
)1(1
1
Frequency Response of inverting
Amplifier
3Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
Vin
Vo
R βR
Sw
s
T
)1(1
1)(
A
V
V
in
o
)1(1
1
jwjw
1
1)(
Tw
1
Phase error:
)(tan 1 w
1, ww
gain error:
11
122
wg
1,2
1 22
wwg
Compensated inverting Amplifier
4Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
Vin
Vo
R βR
)(
VVAVo
0)()0(
1//
)(
R
VV
SC
V
SCR
VVoin
R
V
A
V
R
SC
SCR
SCR
SCR
SCR
V oo
in
1
1
1
1
1
1) Passive Compensation (Wilson)
AC
C/β
)(
VAVo
A
VV o
Compensated inverting Amplifier
5Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
Vin
Vo
R βR
ASCRRCS
RCSA
V
V
in
o
1)1(
)1(
2)1()1(1
1)(
RCSw
Sw
RCSS
TT
1) Passive Compensation (Wilson)
AC
C/βSCRA
RCSA
V
V
in
o
)1(1
)1(
SCRAA
RCS
V
V
in
o
)1(11
)1(
Compensated inverting Amplifier
6Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
Vin
Vo
R βR
2)1()1(1
1)(
RCSw
Sw
RCSS
TT
1) Passive Compensation (Wilson)
AC
C/βFor minimum phase error
RCw
T
)1(
TRw
C)1(
221
1)(
SS
SS
33 w
22
wg
Compensated inverting Amplifier
7Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1) Active Compensation
2
21
21
1
1
2
2
1
)1)(1(11
11
Sww
Sw
Sw
V
V
TTT
T
in
o
Vo
Vin R β1R
β2R
R
A1
A2
Frequency Response of Inverting
Integrator
8Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
)(
VVAVo
AVo
CR
SC
V
R
Voin
1
For ideal op-amp
SCRV
V
in
o1
0
V
oinV
SCR
RV
SCR
SCV11
1
oinV
SCR
SCRV
SCRV
11
1
o
ino VSCR
SCR
SCR
V
A
V
110
SCR
VV
SCR
SCR
A
Vin
o
o
11
Frequency Response of Inverting
Integrator
9Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
AVo
CR
SC
V
R
Voin
1
For ideal op-amp
SCRV
V
in
o1
SCR
VV
SCR
SCR
A
Vin
o
o
11
SCR
V
SCRA
SCRASCRV in
o
1)1(
1
ASCR
A
SCRSCRASCR
A
V
V
in
o
11
1
1
ASCR
SCRV
V
in
o
11
1
11
SwSCR
s
T
11
1
1)(
Frequency Response of Inverting
Integrator
10Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
AVo
CR
CRw
B
1
a)Phase error
1T
B
w
w
TT
T
w
S
CRwSwSCR
s
1
1
1
11
1
1)(
TT
B
w
S
w
ws
1
1)(
Tw
Ss
1
1)(
b)gain error
0)(tan 1
Tw
w
1, TT
w
w
w
w
1
1
12
Tw
wg
1,2
12
TTw
w
w
wg
Compensated Inverting Integrator
11Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Passive Compensation
)(
VVAVo
Vo
C
R
A
VinC1
ooV
SRC
SRCV
SCR
RV
1
1
1
11
oinV
SCR
RV
SCR
SCV11
1
o
in VSCR
SCR
SCR
VV
11
o
in
o
o VSCR
SCR
SCR
VV
RSC
RSC
A
V
1111
1
Compensated Inverting Integrator
12Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Passive Compensation
Vo
C
R
A
VinC1
SCRA
CCRSCCSR
C
C
SRC
SCRV
V
in
o
1
22
11
1
)(1)1(
)1(1
Assume
S
wA T
CRw
B
1
RCw
1
1
1, ,
1
2
11
1
)1(1
)1(
)(
ww
S
w
w
w
S
w
w
w
w
w
S
S
T
B
TT
BB
Compensated Inverting Integrator
13Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Passive Compensation
Vo
C
R
A
VinC1
1
2
11
1
)1(1
)1(
)(
ww
S
w
w
w
S
w
w
w
w
w
S
S
T
B
TT
BB
For minimum phase error
)1(11
11w
w
ww
B
T
TT
B
www
w
w
11
11
BTwww
1
BTwww
RC
11
1
1
Tw
RC1
1 Find 𝜑, g𝜖 ?
Compensated Inverting Integrator
14Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Active Compensation
For Op-Amp 1
0
V
1VV
CR
A1
A2
Vo
Vin V1
inV
SCR
SCV
SCR
RV
1
1
1 1
For Op-Amp 2
oVV
Compensated Inverting Integrator
15Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Active Compensation
1
2
1 VVA
Vo
1
2
2
)1
1)(1
1(
1
11
1
A
SCRA
A
SCRV
V
in
o
CR
A1
A2
Vo
Vin V1
SCR
VV
SCR
SCR
A
Vino
110
1
1
oV
AV )1
1(
2
1
ino
o VV
A
SCRSCR
A
V
2
11
1
)1(
Compensated Inverting Integrator
16Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Active Compensation
1
2
2
)1
1)(1
1(
1
11
1
A
SCRA
A
SCRV
V
in
o
CR
A1
A2
Vo
Vin V1
Sw
S
w
w
S
w
S
S
T
B
T
T
1
2
2
)1)(1(
1
1
)(
CRw
B
1
21
2
2111
2
)1
(1
1
)(
TTTT
B
TT
B
T
ww
S
ww
w
wS
w
w
w
S
S
21
,TTB
www
Compensated Inverting Integrator
17Dr. Mohamed Abd el Ghany
Department of Electronics and Electrical Engineering
ELCT 1003: High Speed
Electronic Circuits
1)Active Compensation
C
R
A1
A2
Vo
Vin V121
2
2111
2
)1
(1
1
)(
TTTT
B
TT
B
T
ww
S
ww
w
wS
w
w
w
S
S
21,
TTBwww
21
2
1
2
11
1
)(
TTT
T
ww
S
wS
w
S
S
For minimum phase error
21 TTww
3
Tw
w
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