Structured Electronic Design Structured Electronic Design ET 8016 - - PowerPoint PPT Presentation

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Structured Electronic Design Structured Electronic Design

• ET 8016
• 5 ECTS credits

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Structured Electronic Design Structured Electronic Design

• Design methodology
• Analysis and Synthesis
• Applied network theory
• Fundamental research
• Free-swinging intellect

Some keywords:

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An amplifier An amplifier

10kΩ

1

R

• 1. What type of amplifier is this?
• 2. When the gain is 10, what is the value of R1?

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Another amplifier Another amplifier

10kΩ

2

R

• 3. When the gain is 100, what is the value of R2?

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And another amplifier And another amplifier

10kΩ

3

R

• 4. When the gain is 2, what is the value of R3?

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And another… And another…

10kΩ

4

R

• 5. When the gain is 20, what is the value of R4?

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• 6. How do you get the crab out?

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Fundamental research Fundamental research

• Why do it this way? (philosophy)
• How to design an amplifier? (techniques)

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11

b

r

π

r

π

c

μ

c

• r
• 7. What is this?

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• 8. Will the lamp light up?

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• 9. Will the lamp light up?

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YES NO

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Tetrahedron Hexahedron Octahedron Dodecahedron Icosahedron

Platonic solids Platonic solids

Edges and angles are all congruent Edges and angles are all congruent

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10.Is this a good model?

It correctly predicts the orbit of all planets you can see with the naked eye.

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Modeling Modeling A correct model gives a correct prediction

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Tetrahedron Hexahedron Octahedron Dodecahedron Icosahedron

Platonic solids Platonic solids

“The five Pythagorean regular polyhedra dictate the structure of the universe and reflect God's plan through geometry”; June19, 1595, Johannes Kepler “The five Pythagorean regular polyhedra dictate the structure of the universe and reflect God's plan through geometry”; June19, 1595, Johannes Kepler

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Modeling Modeling A correct model gives a correct prediction

Never confuse models with “the truth”

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Back to the amplifier… Back to the amplifier…

• 6. What is the current through the load?

10kΩ 10kΩ 1V 1kΩ

Kirchoffs Kirchoffs first law is not obeyed! first law is not obeyed! Kirchoffs Kirchoffs first law is not obeyed! first law is not obeyed!

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Ludwig Wittgenstein(1889-1951)

Language is a labyrinth of paths Language is a labyrinth of paths

Design problems arise from bad formulations Design problems arise from bad formulations

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Amplifier design Amplifier design

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An amplifier with a nullor An amplifier with a nullor

2

R

1

R

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vin=0 vout iout

Nullor Nullor

Input current and input voltage of the nullor are made zero by the output signals of the nullor Input current and input voltage of the nullor are made zero by the output signals of the nullor

iin=0

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Inside the Nullor Inside the Nullor

Norrator Nullator

0? 0? i v = = 0! 0! i v = =

v = i =

Input current and input voltage of the nullor are made zero by the output signals of the nullor Input current and input voltage of the nullor are made zero by the output signals of the nullor

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What is the transfer T of this amplifier? What is the transfer T of this amplifier?

2

R

1

R

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R

R

The transfer T of this amplifier The transfer T of this amplifier

2 1

R T R = −

R

R

• ut

v

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Another transfer T of this amplifier Another transfer T of this amplifier

2 another

T R = −

R

R

• ut

v

i

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Joseph Henry Joseph Henry

The seeds of great discovery are constantly floating around us, but they only take root in minds well prepared to receive them

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R

R

2 1

R T R = −

2 another

T R = −

in in

v i ⎛ ⎞ ⎜ ⎟ ⎝ ⎠

?

• ut
• ut

v i ⎛ ⎞ ⎜ ⎟ ⎝ ⎠

The chain matrix of this amplifier The chain matrix of this amplifier

1

2 2

1

in

• ut

in

• ut

v v i R R R i ⎛ ⎞ − ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ − ⎜ ⎟ ⎝ ⎛ ⎠ ⎞ ⎛ ⎞ = ⎜ ⎟ ⎜ ⎟ ⎝ ⎠ ⎝ ⎠

??

again another

T =

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The two-port and its chain matrix The two-port and its chain matrix

+ +

_ _

vin vout iin iout

⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛

• ut
• ut

in in

i v D C B A i v

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The two-port and its chain matrix The two-port and its chain matrix

• ut

in

• ut i

v A v

=

=

• ut

in

• ut v

v B i

=

=

• ut

in

• ut i

i C v

=

=

• ut

in

• ut v

i D i

=

=

⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛

• ut
• ut

in in

i v D C B A i v

+ +

_ _

vin vout iin iout

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+ + _ _ vin=0 vout iin=0 iout

Nullor Nullor

Input current and input voltage of the nullor are made zero via the output signals of the nullor

⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛

• ut
• ut

in in

i v D C B A i v

in

• ut

in

• ut

v v i i ⎛ ⎞ ⎛ ⎞ ⎛ ⎞ = ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ ⎝ ⎠ ⎝ ⎠ ⎝ ⎠

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Information from source to load

• Signal power is enlarged
• Information stays unaltered

A,B,C,D constant A,B,C,D accurately known A,B,C,D constant A,B,C,D accurately known

A B C D

Accurate amplification Accurate amplification

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A voltage-to-voltage amplifier A voltage-to-voltage amplifier

2 2

1 R R R ⎛ ⎞ ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ − ⎜ ⎟ ⎜ ⎟ ⎝ ⎠ −

2 1 v

R A R = −

2

R

1

R

• ut

v

in

v

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Amplification factor becomes inaccurate.

2

R

1

R

• ut

v

in

v

s

R

2 1 v s

R A R R − + =

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2

R

1

R

• ut

v

in

v

s

R

n

v

( )

2 1 1 2

4 //

n

v s v s

R A R R S kT R R R = − + = +

Optimization Optimization

Information is disturbed Amplification factor still inaccurate.

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2

R

1

R

• ut

v

in

v

s

R

Change topology Change topology

1 2 1 1 2

4 ( // )

n

v v s

R R A R S kT R R R + = = +

Orthogonalization Orthogonalization

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2

R

1

R

• ut

v

in

v

s

R

1 2 1 1 2 1 2

4 ( // )

n

v v s

• ut

fb

R R A R S kT R R R v i R R + = = + = +

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Orthogonalization

Optimization

Orthogonalization

Optimization

R

R

• ut

v

v

R

R

R

• ut

v

v

R

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• ut

v

in

v

s

R n 1

4

n

v v s fb

A n S kTR i = = =

1 2 1 1 2 1 2

4 ( // )

v v s

• ut

fb

R R A R S kT R R R v i R R + = = + = +

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Right choice

Orthogonalization

Optimization

Right choice

Orthogonalization

Optimization

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The “right” choice:

• Start? (as usual?)
• Analyze?
• Optimize?
• Orthogonality?
• Specifications?
• Criteria?

The “right” choice:

• Start? (as usual?)
• Analyze?
• Optimize?
• Orthogonality?
• Specifications?
• Criteria?

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N N S B C + = log

2

The criteria The criteria

• 1. Noise
• 2. Signal power (distortion)
• 3. Bandwidth
• 1. Noise
• 2. Signal power (distortion)
• 3. Bandwidth

And what about supply voltage, current, power consumption, technology etc.?

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• Optimization
• Orthogonalization

Correlated properties Correlated properties

1. Noise 2. Signal power (distortion) 3. Bandwidth 1. Noise 2. Signal power (distortion) 3. Bandwidth

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• Properties are generally not orthogonal
• But design as if
• Make it right

Orthogonal properties (2) Orthogonal properties (2)

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When optimizing non-linear behavior (distortion):

• No dynamic effects
• No noise

When optimizing bandwidth:

• Small-signal models (no non-linearity)
• No noise

When optimizing noise behavior:

• Small-signal models (no non-linearity)
• No bandwidth details

As if… As if…

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bandwidth – noise – distortion bandwidth – distortion - noise noise - bandwidth – distortion noise – distortion - bandwidth distortion - noise – bandwidth distortion – bandwidth - noise

The most orthogonal sequence? The most orthogonal sequence?

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• Is it a cow?
• Is it green?
• Is it an animal?

Know which problem to solve first Know which problem to solve first

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See the structure: Create Hierarchy! See the structure: Create Hierarchy!

Detail

∫

Σ

Global

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• The right design step at the right time
• A design step occurs only once

Orthogonality, hierarchy, classification

Efficient design Efficient design

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Reduce the search space as fast as possible.

Look for “fast” criteria:

• Necessary but not sufficient (e.g. LP -product)

Extensive calculations only when it “makes sense”

• Simplest model that suffices

Efficient design (2) Efficient design (2)

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Attitude Attitude

• Know exactly what you want
• Use second best, if you can’t have it
• Know the penalty

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Voltage amplifier, what’s in the nullor? Voltage amplifier, what’s in the nullor?

Nullor

S

• urce

Load

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Inside the Nullor Inside the Nullor

Norrator Nullator

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Nullator? Norrator? Nullator? Norrator?

Norrator Nullator

v = i =

Current sensor Voltage sensor Current source Voltage source

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practical nullor implementations practical nullor implementations

i v v i

A B C D

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Choose Choose

Nullor

S

• urce

Load

i v v i

A B C D

i v v i

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The experts with practical experience… The experts with practical experience…

v

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Loopgain with B-type block Loopgain with B-type block

Source

v

Load

1

R

2

R

L

R

L

C

1 1 2

1 1 1 B

L L L L L L

R j R C L R R R R j R C ω ω ⎛ ⎞ ⎜ ⎟ + ⎜ ⎟ = ⎜ ⎟ + + ⎜ ⎟ + ⎝ ⎠

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Loopgain with A-type block Loopgain with A-type block

1

R

2

R

v

Source Load

L

R

L

C

1 1 2

1 A R L R R ⎛ ⎞ = ⎜ ⎟ + ⎝ ⎠

1 1 2

1 1 1 B

L L L L L L

R j R C L R R R R j R C ω ω ⎛ ⎞ ⎜ ⎟ + ⎜ ⎟ = ⎜ ⎟ + + ⎜ ⎟ + ⎝ ⎠

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Which transistor stage? Which transistor stage?

R

R

v

Source Load

R

C

+ + + + + +

• +

+ + + + +

• CE-stage

CB-stage CC-stage Differential CE-stage Differential CB-stage Differential CC-stage

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Voltage amplifier with A-type block Voltage amplifier with A-type block

1

R

2

R

Source Load

L

R

L

C

R

R

v

Source Load

R

C

1 1 2

1 A R L R R ⎛ ⎞ = ⎜ ⎟ + ⎝ ⎠

L<1

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Back to the B-type solution (told you so….) Back to the B-type solution (told you so….)

1

R

2

R

Source Load

L

R

L

C

1 1 2

1 1 2 1 1

L L L L E L L C

R j R L C R R R j R B C R ω ω ⎛ ⎞ ⎜ ⎟ + ⎜ ⎟ ⎜ ⎟ + + ⎜ ⎟ + ⎝ ⎠ = >

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The “expert” solution The “expert” solution

1

R

2

R

Source Load

L

R

L

C 2 o r

• Miller effect
• Distortion
• Miller effect
• Distortion

1 1 2

1 1 lim 2 1 B 1 D

• L

L L r L CE L C L C

R j R C L R R R R j R C ω ω

→∞

⎛ ⎞ ⎜ ⎟ + ⎜ ⎟ = ⎜ ⎟ + + ⎜ ⎟ + ⎝ ⎠ B A

CE CE

• r

=

( ) ( )

1 1 1 2 1 A A D 1

• CC

R R R j R R L C R R R j R C R R R j R C r R R R R j R C R ω ω ω ω ⎛ ⎞ + ⎜ ⎟ + ⎜ ⎟ ⎜ ⎛ ⎞ = ⎜ ⎟ + ⎝ ⎟ + + ⎜ ⎟ + ⎝ ⎠ ⎛ ⎞ + ⎜ ⎟ + ⎜ ⎟ + ⎜ ⎟ + + ⎜ ⎟ + ⎝ ⎠ ⎠

ro

s h

• u

l d b e

low ???

ro

s h

• u

l d b e

low ???

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“Expert” versus “logic” “Expert” versus “logic”

R

R

Source Load

R

C 2 o r

R

R

Source Load

R

C

1 1 2

1 1 1 1 2B D

L CE CC L L L L L

R j R C R R R j R R L C ω ω ⎛ ⎞ ⎜ ⎟ + ⎜ ⎟ ⎜ ⎟ + + ⎜ + ⎝ ⎠ = ⎟

☺ no miller effect ☺ less distortion Load dependent loopgain ☺ no miller effect ☺ less distortion Load dependent loopgain miller effect first stage distortion and clipping first stage ☺ Loopgain not(less) load dependent miller effect first stage distortion and clipping first stage ☺ Loopgain not(less) load dependent

( ) ( )

1 1 1 2 1 A A D 1

• CC

R R R j R R L C R R R j R C R R R j R C r R R R R j R C R ω ω ω ω ⎛ ⎞ + ⎜ ⎟ + ⎜ ⎟ ⎜ ⎛ ⎞ = ⎜ ⎟ + ⎝ ⎟ + + ⎜ ⎟ + ⎝ ⎠ ⎛ ⎞ + ⎜ ⎟ + ⎜ ⎟ + ⎜ ⎟ + + ⎜ ⎟ + ⎝ ⎠ ⎠

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Which solution when? Which solution when?

R

R

Source Load

R

C 2 o r

R

R

Source Load

R

C

☺ no miller effect ☺ less distortion Load dependent loopgain ☺ no miller effect ☺ less distortion Load dependent loopgain miller effect first stage distortion and clipping first stage ☺ Loopgain not(less) load dependent miller effect first stage distortion and clipping first stage ☺ Loopgain not(less) load dependent

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Alternatives Alternatives

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Conclusions Conclusions

• Know ideal case
• Know the penalty for choosing second best
• Beware of experts !
• Always remember the ideal case!

The seeds of great discovery are constantly floating around us, but they only take root in minds well prepared to receive them