from kcl to class d amplifier - esat.kuleuven.be · osterrieth, bernard paulus, dimitri pfeiffer,...
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From KCL to Class D AmplifierFrancis Labrique
Charles TrullemansUCL School of EngineeringLouvain-la Neuve Belgium
CAS Education WorkshopSeattle 2008
2ISCAS 2008Ch. TrullemansF. Labrique (EPL)
CAS in the EPL Bachelor program
Year 11st term
2d term
~ 350 studentsany engineering program
~ 90 studentsmajor or minor program in electricity
Year 2
Year 3
1st term
2d term
1st term
2d term
Physics : mechanics, electricity
ElectromagnetismProject: electricity, material science
Circuit theoryProject: circuits
Applied MathemathicsElectronic circuitsDevice physicsTelecom
Bachelor degree
This talk
3ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Objectives
charge flow
Starting point
Bottom-uplearningprocess
Functional view
∫ΣΔ Class D amplifier
Circuit view
Kirchhoff network
4ISCAS 2008Ch. TrullemansF. Labrique (EPL)
CAS in the EPL Bachelor program
Year 11st term
2d term
Physics : mechanics, electricity
Electromagnetism
Project: electricity, material science
Active learning based program
Lectures+ multidisciplinary problem solving+ projects & team work
5ISCAS 2008Ch. TrullemansF. Labrique (EPL)
1st year , 1st term: basic physics
• Fundamental concepts– charge, current, voltage, fields, energy, power …
I
V
Physics:movingchargein an
electricfield
Circuit:power
to/from any
dipole
A
B
3dl I
3E I
Q
links
6ISCAS 2008Ch. TrullemansF. Labrique (EPL)
From Physics to Circuits
• Device modeling: R, C, L
• Elements constraints I V
R
I V
L
I V
C
ρE
σ
ε
μ
σ
ε
μ
= =
= = =
= = =
2
2
1212
G
C C
L L
G g V R IdVC g I C W C Vdt
dIL g V L W L Idt
Underlying physics
Functional model
Just in time: a little touch of Coulomb, Gauss, Biot-Savart, Faraday …
Electromagnetism course to follow, 2d term
links
7ISCAS 2008Ch. TrullemansF. Labrique (EPL)
• Circuit theory– Network constraints: KCL, KVL
– Voltage and current sources
– Equivalent dipoles
• Focusing on 1st order dynamic circuits
From Physics to Circuits
VS
VCR1
R2 C
Circuit theory course to follow, 2d year
ReqVC
Veq C
8ISCAS 2008Ch. TrullemansF. Labrique (EPL)
First Order System
• Dynamic behaviour– Energy
Constant at equilibrium
No instantaneous change
Mechanics
– Voltage time derivative ∝ distance to equilibrium
R
CI
VC ( t )
VS
( )1CC C
dVV V
dt τ ∞= −
links
Derivative vector plotsee: Thomas Calculus p. 644 et 645
tt
VC
links
Their Math textbook
9ISCAS 2008Ch. TrullemansF. Labrique (EPL)
What they do
• Pick up a formula or recipe• Use formal calculus• Don’t bother with all those words or schematics• Keep a secure and tight border between different courses and topics
Archimedes, what, what is that fish formula?
Who? Who? What? What? What?
You know, that... Latin business.
Aquarius aquaticus aqualitus.
The Sword and the StoneDisney 1963
10ISCAS 2008Ch. TrullemansF. Labrique (EPL)
1st year , 2d term
• Build a brushless DC motor + driver– Real life context
– Lab equipment
Stator
Rotor
G
S
D
=
Switch
Buehler standard DC motors
to be replaced by brushless motors
Also: flash lamp, loudspeaker, DC-DC converter
11ISCAS 2008Ch. TrullemansF. Labrique (EPL)
What they do
• Hands on – Oscilloscope, waveforms
– Components
– Measurements & errors
• Problem solving– How to reverse
the magnetic flux?
– How to swicth an inductance current?
• Modeling– Schematics ↔ workbench
Abstract model ≠ virtual reality
12ISCAS 2008Ch. TrullemansF. Labrique (EPL)
CAS in the EPL Bachelor program
Year 21st term
2d term Circuit theoryProject: circuits
Coordinated contents and schedules
2 professors + 2 assistants + 1 technician + 7 tutors (last year master students) = 121 hour staff meeting every week
14 groups of 6 students = 846 hours presential time / week : lecture + exercises + lab
Year 1 Physics course
François BaudartOlivier BulteelThierry DarasJonathan DeniesJulien DevosLaurent DevroeyeThibaut LabbéFrancis LabriqueChristophe MouvetStan SobieskiCharles TrullemansChristophe Vloebergh
13ISCAS 2008Ch. TrullemansF. Labrique (EPL)
1st year , 2d term: course+project
• Course– Circuit theory
– Op Amps
– Phasors• Bode diagram
– Fourier (basics)• Wave spectrum
– Laplace (basics)• Functional
modeling
• Project
– Circuit analysis & design
– Simulation
– Experimentation
– Class D amplifier:
a mix of linear and non-linear circuits
Applied maths course to follow, 3d year
Challenging projectfor the studentsfor the staff
a keystone of motivation
links
links
links
links
14ISCAS 2008Ch. TrullemansF. Labrique (EPL)
The way of the future ?
Class D amplifiers
The official product launch of Elite SC-09TX
will take place at the CES in Las Vegas
on January 7-10.Nu-Force Class D Amplifier
Week 1: Introduction
Motivation is a keystone of learning
15ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Starter: 1-pole Op-Amp circuit
• Paper and pencil
Spice
Experiment
Objectives
• Analysis
• Determining components from a specification
Vout
Cint
Rf
Zf
Vin Rint
X
16ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Project core: ΣΔ Schematic
• Mission– What is this ?
– How does it work ?
– Calculate components values according to specs
– Design another PWM modulator
0
R1
7.7
R2
7.7
V1DC = 15V
V2
DC = 15V
VEE
VCC
VEE OUT7
+2
-3 G 1
V+
8V
-4
B/S6B
5U1
LM111
VCC
VEE 0
VCC
R201k
R12
7.7
R11
7.7
0C1
7.7
0
+
-
OUT
U2
OPAMP
A
R3
7.7Vin
FREQ = 7kHzVAMPL = 7
0
B
Input specs: phone signal Output spec: PWM, < 50 kHz
17ISCAS 2008Ch. TrullemansF. Labrique (EPL)
What they do
0
R1
7.7
R2
7.7
V1DC = 15V
V2
DC = 15V
VEE
VCC
VEE OUT 7+2
-3
G1
V+
8V
-4
B/S 6B5U1
LM111
VCC
VEE 0
VCC
R201k
R12
7.7
R11
7.7
0C1
7.7
0
+
-
OUT
U2
OPAMP
A
R3
7.7Vin
FREQ = 7kHzVAMPL = 7
0
B
DC or sin
Time
100us 150us 200us 250us 300usV(PWM)
0V
15V
VB: PWM
Time
100us 150us 200us 250us 300usV(integr)
0V
-1.2V
VA: triangular
Every groupachievesHand calculationSimulationExperiment
Several groupsachieveDesign
18ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Building PWM modulators
Group 11 final report
19ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Week 8: Preliminary report
• Walking in darkness
The output voltage will be a triangular signal. The rising and falling edge will have exactly opposed slopes.
We are looking for a ratio between R1 and R2. If the voltage at the common node is 0, we get:
We also want the current through C1 when VB » 15 to be exactly opposed to the current at the same place when VB = 0. This gives:
1 1 2 20 15 0− = − + =B R RV R I R I
( )1 2 2− = − −R R RI I I
Group 10 preliminary report
Schematic
driven
approach.
Is the purpose
of this circuit
to produce a
symmetric
triangular
wave ??
20ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Just in time teaching ( 1 hour )
1. Find the functional blocks border lines
2. Identify the interface signals
3. Derive the circuit details from the overall structure
Sum
PWM
Signal Integral Hysteresis
21ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Week 13: Final report
• A great light
When the input signal is null, the mean value of the PWM signal must be null too.
Group 10 final report
The integrator aims at obtaining a mean error voltage from an error current. The steepest slope occurs when the input signal is close to 0.
Sound
reasoning
22ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Week 14: What they do
∫
Group 9 final report
in:sine wave PWM output
spectrum
0
R1
7.7
R2
7.7
V1DC = 15V
V2
DC = 15V
VEE
VCC
VEE OUT 7+
2
-3
G1
V+
8V
-4
B/S6B
5U1
LM111
VCC
VEE 0
VCC
R201k
R12
7.7
R11
7.7
0C1
7.7
0
+
-
OUT
U2
OPAMP
A
R3
7.7VinFREQ = 7kHz
VAMPL = 7
0
B
Severalgroupsachieve Top-downsystemdescription
23ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Outcomes
• End result– Working amplifiers ( at least 1/group )
– Listening to the beloved mp3 player through the amplifier (wow !)
• Learning experience– Important steps, part of a progressive process
– Long term competences acquired from now on
• Better perception of the real issue– To pass the exam
– To become a designer
24ISCAS 2008Ch. TrullemansF. Labrique (EPL)
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Bosly, Damien Bouvy, Nicolas Charlier, Benoît Clabots, Martin Coenen, Damien Coppens, Numa Couniot, Vincent Cousin, Simon Crelot, Gatien De Bast, Olivier de Caritat de Peruzzis, Guerric de Crombrugghe de
Looringhe, Charles De Groote, Emmanuel De Neyer, Laetitia de Viron, Adeline Decuyper, Philippe Delandmeter, Olivier Descamps, Nathan Devreese, Diego d'Ursel, Christophe Everarts, Thomas François, Rodolphe Gilliot, Simon Godfrind, Gabriel Gorza, Brieuc Grégoire, Denis Grogna, Pierre-Antoine Haddad,
Benoît Herbin, Julien Jomaux, Simon Labbé, Laurent Lamouline, Sébastien Leboutte, Quentin Leirens, Nicolas Lequin, Nicolas Luyckx, Cédric Marchand, Maxime Marion, Pierre Marot, Michael Marrocco, Guillaume Martin, Grégoire Masquelier, Sébastien Matton, Céline Michel, Laurent Michiels, Philippe Michiels, Justin Morel de Westgaver, Muhire Boniface Nteziyaremye Ntwali, Vincent Nuttin, Cédric
Osterrieth, Bernard Paulus, Dimitri Pfeiffer, Louis Philipperon, Louis-Antoine Pirnay, Olivier Poncelet, Aimé Pouahoulabou, Marie-Anne Pungu Mwange, Alexandre Saint, Alessandro Sarich, Pierre-Yves Sévar, Pierre Slinckx, Cédric Snauwaert, Alexandre Thissen, Nicolas Van den Berge, Eric van den Hove, Pierre-
Hugues Van houte, Aymeric Van Outryve d'Ydewalle, Nicolas Vansnick, Thomas Vansnick, Daniel Vergeylen, Bertrand Vosse, Abdullah Yogurtcu
Thanks
25ISCAS 2008Ch. TrullemansF. Labrique (EPL)
Traditional CAS education The way of the future ?
A question