Electronic Circuits for Mechatronics
(ELCT 609)
Summer 2020 : Round II
Lecture 11: Op-amp Linear and Non-linear
Applications
Course Instructor: Dr. Eman Azab
1
Op-amps: IntroductionCircuit Modeling
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
2
mailto:[email protected]
Ideal Op-amp Operational amplifiers are
voltage amplifiers with very highgain
Differential Input/Single outputcircuit is the most famous op-amp structure
Ideal op-amp have the followingSpecs:
Infinite Differential voltagegain
Zero Common-modevoltage gain
Infinite Input Resistance
Zero Input Currents
Zero Output Resistance
Infinite Bandwidth (Gain isconstant all over thefrequency Spectrum)
๐๐๐ข๐ก = ๐ด๐๐ ๐1 โ ๐2 + ๐ด๐๐๐๐1 + ๐2
2
๐ด๐๐ = โ ๐ด๐๐๐ = 0
๐ ๐๐ = โ ๐ ๐๐ข๐ก = 0
๐ด๐๐ ๐ = ๐ถ๐๐๐ ๐ก.
๐๐๐+ = 0 ๐๐๐โ = 0
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
3
Operational amplifiers arevoltage amplifiers with very highgain
Differential Input/Single outputcircuit is the most famous op-amp structure
Ideal op-amp have the followingSpecs:
Infinite Differential voltagegain
Zero Common-modevoltage gain
Infinite Input Resistance
Zero Input Currents
Zero Output Resistance
Infinite Bandwidth (Gain isconstant all over thefrequency Spectrum)
๐๐๐ข๐ก = ๐ด๐๐ ๐1 โ ๐2 + ๐ด๐๐๐๐1 + ๐2
2
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Ideal Op-amp Ideal Op-amp can be modeled using the following circuit:
๐๐๐ข๐ก = ๐ด๐๐ ๐1 โ ๐2 + ๐ด๐๐๐๐1 + ๐2
2
๐ด๐๐ = โ ๐ด๐๐๐ = 0
๐ ๐๐ = โ ๐ ๐๐ข๐ก = 0
๐ด๐๐ ๐ = ๐ถ๐๐๐ ๐ก.
๐๐๐+ = 0 ๐๐๐โ = 0Figure from Sedra/Smith Copyright ยฉ 2010 by Oxford University Press, Inc.
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
4
mailto:[email protected]
Non-ideal Op-ampCircuit Realizations of Op-amp
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
5
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Ex.: Two stage CMOS Op-amp
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
6
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Ex.: BJT 741 Op-amp
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
7
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Op-amp Applications
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
8
mailto:[email protected]
Voltage Amplifier
Inverting and Non-Inverting Amplifiers
๐ฃ๐๐ฃ๐ผ
= โ๐ 2๐ 1
๐ฃ๐๐ฃ๐ผ
= 1 +๐ 2๐ 1
Figures from Sedra/Smith Copyright ยฉ 2010 by Oxford University Press, Inc.
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
9
mailto:[email protected]
Voltage Amplifier
Inverting Amplifiers
๐ฃ๐๐ฃ๐ผ
= โ๐ 2๐ 1
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
10
mailto:[email protected]
Voltage Buffer
Voltage Buffer
The voltage at the input is derived at the output node
without drawing any current from the input source
๐ฃ๐๐ฃ๐ผ
= 1
Figure from Sedra/Smith Copyright ยฉ 2010 by Oxford University Press, Inc.
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
11
mailto:[email protected]
Voltage Difference Amplifier
The circuit subtracts two voltage signals
By Applying Superposition principle between ๐ฃ๐ผ1 and ๐ฃ๐ผ2
By Choosing:
๐ฃ๐ = โ๐ฃ๐ผ1๐ 2๐ 1
+ ๐ฃ๐ผ2๐ 4
๐ 4 + ๐ 31 +
๐ 2๐ 1
๐ 2๐ 1
=๐ 4๐ 3
๐ฃ๐ =๐ 2๐ 1
๐ฃ๐ผ2 โ ๐ฃ๐ผ1
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
12
mailto:[email protected]
Voltage Integrator
Inverting configuration with General Impedances
Lossless inverting Integrator
๐๐๐๐
= โ๐2๐1
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
13
mailto:[email protected]
Voltage Integrator
Lossy Integrator
DC Gain is defined by:
๐ฃ๐๐ฃ๐
= โ
๐ ๐น๐
1 + ๐ ๐ถ๐ ๐น
๐ฃ๐๐ฃ๐(0) = โ
๐ ๐น๐
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
14
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Voltage Differentiator
Op-amp based Differentiator
๐ฃ๐๐ฃ๐(๐ ) = โ๐ ๐ถ๐
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
15
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Voltage Weighted Summer
Figure from Sedra/Smith Copyright ยฉ 2010 by Oxford University Press, Inc.
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
16
mailto:[email protected]
Voltage Comparator
Figure from Sedra/Smith Copyright ยฉ 2010 by Oxford University Press, Inc.
Positive Feedback is employed
The output voltage is either the high or the low voltagesupply
๐ฃ๐ < ๐ฃ+ ๐ฃ๐ = ๐๐ถ๐ถ
๐ฃ๐ > ๐ฃ+ ๐ฃ๐ = ๐๐๐
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
17
mailto:[email protected]
Voltage Logarithmic Amplifier Non-linear logarithmic Amplifier
BJT operates in the Active Region
๐๐๐ข๐ก = โ๐๐ต๐ธ = โ๐๐๐๐๐ผ๐ถ๐ผ๐
๐ผ๐ถ =๐๐๐๐ 1
๐๐๐ข๐ก = โ๐๐ต๐ธ = โ๐๐๐๐๐๐๐๐ผ๐๐ 1
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
18
mailto:[email protected]
Voltage anti-Logarithmic Amplifier
Non-linear Anti-logarithmic Amplifier
BJT operates in the Active Region
๐๐๐ = โ๐๐ต๐ธ = โ๐๐๐๐๐ผ๐ถ๐ผ๐
๐ผ๐ถ =๐๐๐ข๐ก๐ 1
๐๐๐ข๐ก = ๐ผ๐๐ 1expโ๐๐๐๐๐
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
19
mailto:[email protected]
Voltage Multiplier or Divider
๐๐๐ข๐ก = ๐ผ๐๐ 1expโ๐๐๐๐๐
๐๐๐ข๐ก = โ๐๐ต๐ธ = โ๐๐๐๐๐๐๐๐ผ๐๐ 1
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
20
mailto:[email protected]
Example
For the 4127 IC showed in figure, find the output voltage (Vout) as a function in the input currents (Ix and Iy).
Using the 4127 IC and the linear/nonlinear op-amp applications, design the following functions with minimum number of op-amps and derive K, n and m as a function in the circuit parameters.
Note that: Q1 and Q2 are matched and ฮฒ is large.
๐๐๐ข๐ก = ๐พ๐ผ๐ฅ๐ผ๐ฆ
๐
๐๐๐ข๐ก = ๐พ๐ผ๐ฅ๐ผ๐ฆ
๐โ๐
Course Instructor: Dr. Eman Azab
Contact: [email protected]
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
21
mailto:[email protected]
Example Solution
For the 4127 IC showed in figure, find the output voltage (Vout) as a function in the input currents (Ix and Iy).
Note that: Q1 and Q2 are matched and ฮฒ is large.
Electronic Circuits for Mechatronics ELCT 609
Summer R2 2020
22