Mixed-Signal-Electronics - Lehrstuhl für Technische Elektronik - TUM
Mixed-Signal-Electronics - Lehrstuhl für Technische Elektronik - TUM
Mixed-Signal-Electronics - Lehrstuhl für Technische Elektronik - TUM
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<strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong><br />
PD Dr.-Ing. Henzler<br />
Prof. Dr. Schmitt-Landsiedel<br />
<strong>Lehrstuhl</strong> <strong>für</strong> <strong>Technische</strong> <strong>Elektronik</strong><br />
<strong>Technische</strong> Universität München<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
1
<strong>Mixed</strong>-<strong>Signal</strong>-Team<br />
Prof. Dr. Schmitt-Landsiedel<br />
dsl@tum.de<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
PD Dr. Henzler<br />
henzler@tum.de<br />
2
Stephan‟s ambition for this course …<br />
Simplicity is the Ultimate Sophistication<br />
Leonardo Da Vinci<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
But don‟t misunderstand,<br />
this does not mean that you<br />
don‟t have to exercise!<br />
3
Course and Online Material<br />
Lecture notes<br />
available in the Fachschaft EI (<strong>TUM</strong>), handout (GIST <strong>TUM</strong> Asia)<br />
Online material comprising<br />
– annotated slides<br />
– video stream of past lectures (GIST <strong>TUM</strong> Asia)<br />
www.lte.ei.tum.de/homes/henzler<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
4
Student Discussion Forum<br />
Ask questions online … other students can benefit, too<br />
Try to answer other questions … improves your<br />
understanding<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
5
Administratives<br />
Lecture: Stephan Henzler<br />
henzler@tum.de<br />
office hours: online consultation<br />
Tutorial: Nasim Pour Aryan<br />
n.aryan@tum.de<br />
office hours online & by arrangement<br />
Exam: in written form,<br />
preliminary date February, 14th 2012, 14:00 (<strong>TUM</strong>)<br />
Credits: 4.5 ECTS credits (<strong>TUM</strong>)<br />
Language: english<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
6
“Today everything is digital –<br />
Why do we need <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong>?”<br />
Digital System, e.g.<br />
- digital communication<br />
(DSL, GSM, …, LTE)<br />
- computer equipment<br />
- multimedia<br />
(DVD, mp3, camera… )<br />
- control application<br />
(e.g. automotive)<br />
discrete sequence of<br />
numbers from a discrete set<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
7
The Macroscopic World is Purely Analog<br />
motion/acceleration<br />
mechanical force<br />
sound waves<br />
light<br />
electromagnetic<br />
field<br />
Digital System, e.g.<br />
- digital communication<br />
(DSL, GSM, …, LTE)<br />
- computer equipment<br />
- multimedia<br />
(DVD, mp3, camera… )<br />
- control application<br />
(e.g. automotive)<br />
discrete sequence of<br />
numbers from a discrete set<br />
The mixed-signal shell is a bridge between<br />
temperature sense organs<br />
– the analog environment and the digital signal processing<br />
– the physical representation (voltage/current) and a mathematical abstraction<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
sensors/<br />
actuators<br />
time<br />
even „digital‟<br />
signals on a<br />
transmission<br />
channel<br />
8
The Macroscopic World is Purely Analog<br />
motion/acceleration<br />
mechanical force<br />
sound waves<br />
light<br />
electromagnetic<br />
field<br />
ADC<br />
DAC<br />
Digital System, e.g.<br />
- digital communication<br />
(DSL, GSM, …, LTE)<br />
- computer equipment<br />
- multimedia<br />
(DVD, mp3, camera… )<br />
- control application<br />
(e.g. automotive)<br />
discrete sequence of<br />
numbers from a discrete set<br />
The mixed-signal shell is a bridge between<br />
temperature sense organs<br />
– the analog environment and the digital signal processing<br />
– the physical representation (voltage/current) and a mathematical abstraction<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
sensors/<br />
actuators<br />
time<br />
even „digital‟<br />
signals on a<br />
transmission<br />
channel<br />
9
Generic <strong>Mixed</strong> <strong>Signal</strong> System<br />
What means mixed-signal?<br />
<strong>Mixed</strong>-signal refers to a system which processes both analog<br />
and digital signals and which contains converter blocks that<br />
enable interaction between the two domains.<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
10
Topics of MSE Course<br />
Structure of mixed signal systems and mathematical<br />
representation of discrete time signals.<br />
ADC<br />
discrete time<br />
discrete states<br />
discrete time (step function)<br />
continuous states<br />
Lecturer Page Version<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
digital discrete time (step function)<br />
discrete values (states)<br />
11
Sample & hold circuits<br />
Topics of MSE Course<br />
Switched-capacitor circuits<br />
Data converter fundamentals (ADC, DAC)<br />
converter parameters and characteristics<br />
Nyquist rate D/A Converters<br />
Nyquist rate A/D Converters<br />
Oversampling Converters<br />
Outlook: More mixed signal building blocks<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
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Recommended Literature<br />
David A. Jones<br />
Ken Martin<br />
Analog Integrated Circuit Design<br />
(no picture for copyright reasons)<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
Relevant chapters:<br />
Chapter 7:<br />
Comparators.<br />
Chapter 8:<br />
Sample-and-Holds<br />
Chapter 9:<br />
Discrete Time <strong>Signal</strong>s<br />
Chapter 10:<br />
Switched Capacitor Circuits<br />
Chapter 11:<br />
Data Converter Fundamentals<br />
Chapter 12:<br />
Nyquist-Rate D/A Converters<br />
Chapter 13:<br />
Nyquist-Rate A/D Converters<br />
Chapter 14:<br />
Oversampling Converters<br />
13
Additional Literature & References<br />
Razavi. Principles of Data Conversion System Design.<br />
Wiley, 1994.<br />
Allen, Holberg. CMOS Analog Circuit Design. Oxford, 2010.<br />
Baker, Li, Boyce. CMOS Circuit Desig, Layout, Simulation.<br />
Wiley, 1997.<br />
Gregorian, Temes. Analog MOS Integrated Circuits for<br />
<strong>Signal</strong> Processing. Wiley 1986.<br />
Oppenheim. Zeitdiskrete <strong>Signal</strong>verarbeitung. Oldenbourg<br />
1999.<br />
Norsworthy, Schreier, Temes. Delta-Sigma Data<br />
Converters. IEEE Press, 1997.<br />
Schreier, Temes. Understanding Delta Sigma Data<br />
Converters. IEEE Press 2005.<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
14
Constraints of <strong>Mixed</strong> <strong>Signal</strong> Circuits in SoC<br />
PROS CONS<br />
• Cheap implementation of complex<br />
signal processing tasks<br />
• System-on-chip (SOC)<br />
Small pcb footprint<br />
• Fast time reference/clock<br />
• Digitally assisted analog<br />
• All advantages of digital<br />
systems, e.g. robustness, noise<br />
immunity, data storage,<br />
reconfigurability, efficient highly<br />
automated design and test<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
• Need to build analog circuits in<br />
digital process, i.e.<br />
• Devices optimized for high<br />
switching speed not for analog,<br />
(e.g. small gm/gds)<br />
• Transistors with high field<br />
and short channel effects<br />
µ(V G), V th(W,L,V DS,V BS), I gate, I DB<br />
• <strong>Signal</strong> contamination due to digital<br />
switching noise, e.g. cross talk,<br />
supply noise substrate coupling<br />
• several 100mA digital currents<br />
• V analog signals<br />
15
Generic Structure of <strong>Mixed</strong>-<strong>Signal</strong> Systems<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
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Representation of Discrete Time <strong>Signal</strong>s and<br />
Spectral Transformation<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
17
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12 18
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12 19
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
20
Representation of Discrete Time <strong>Signal</strong>s and<br />
Spectral Transformation<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
21
Representation of Discrete Time <strong>Signal</strong>s and<br />
Spectral Transformation<br />
Spectrum of a sampled signal:<br />
s(t) = X<br />
±(t ¡ nT ) $ S(!) = 2¼<br />
T<br />
n<br />
xs(t) = xc(t) ¢ s(t) $<br />
Sampling means multiplication<br />
of continuous time signal with<br />
pulse train<br />
X<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
k<br />
±(! ¡ k!s) !s = 2¼<br />
T<br />
Xs(!) = 1<br />
2¼ Xc(!) ¤ S(!)<br />
= 1<br />
T Xc(!) ¤ X<br />
= 1<br />
T<br />
X<br />
k<br />
In frequency domain this translates<br />
into convolution of signal spectrum<br />
with spectrum of pulse train.<br />
This is simply a copy and shift of<br />
the spectrum to multiples of the<br />
sampling frequency<br />
k<br />
Xc(! ¡ k!s)<br />
±(! ¡ k!s)<br />
22
Representation of Discrete Time <strong>Signal</strong>s and<br />
Spectral Transformation<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
23
Aliasing in the Frequency Domain<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
t<br />
t<br />
t<br />
t<br />
t<br />
t<br />
24
amplitude fsampling = 1 f signal,1 = 0.22<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0<br />
-0.2<br />
-0.4<br />
-0.6<br />
-0.8<br />
-1<br />
Sampling and Aliasing 1<br />
0 5 10 15<br />
samples<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
25
amplitude fsampling = 1 f signal,2 = 0.22 + fsampling<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0<br />
-0.2<br />
-0.4<br />
-0.6<br />
-0.8<br />
-1<br />
Sampling and Aliasing 2<br />
0 5 10 15<br />
samples<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
26
amplitude<br />
1<br />
0.8<br />
0.6<br />
0.4<br />
0.2<br />
0<br />
-0.2<br />
-0.4<br />
-0.6<br />
-0.8<br />
-1<br />
Sampling and Aliasing 3<br />
Only with the Nyquist criterion it is assured that the samples<br />
represent the signal unambiguously<br />
0 5 10 15<br />
samples<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
27
Remember: All realizable signals have<br />
–<br />
–<br />
–<br />
Practical Sampling: Sample & Hold<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
t<br />
t<br />
t<br />
28
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
29
Practical Sampling: Sample & Hold<br />
Remember: All realizable signals have<br />
– finite slope<br />
– finite pulse width<br />
– finite bandwidth<br />
– finite value<br />
Hence sampling means always SAMPLE & HOLD<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
30
Sampling with Finite Pulse Width<br />
x sh(t) = xs(t) ¤ h(t)<br />
=<br />
x sh(!) = 1<br />
¿<br />
= 1<br />
¿<br />
1X<br />
n=¡1<br />
+1<br />
Z<br />
¡1<br />
1X<br />
= ¡ 1<br />
j!¿<br />
xc[n] 1<br />
¿ [¾(t ¡ nT ) ¡ ¾(t ¡ nT ¡ ¿)]<br />
1X<br />
n=¡1<br />
n=¡1<br />
1X<br />
xc[n]<br />
n=¡1<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
xc[n] [¾(t ¡ nT ) ¡ ¾(t ¡ nT ¡ ¿)] e ¡j!t dt<br />
nT +¿<br />
Z<br />
nT<br />
e ¡j!t dt<br />
xc[n] h<br />
e ¡j!ti nT +¿<br />
nT<br />
(t)<br />
t<br />
31
Xsh(!) = ¡ 1<br />
j!¿<br />
Sampling with Finite Pulse Width<br />
=<br />
1X<br />
n=¡1<br />
Distortion of base band and damping of mirror spectra<br />
– visible in DAC<br />
– not visible in ADC<br />
1X<br />
n=¡1<br />
xc[n]e ¡j!nT<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
xc[n] ³<br />
e ¡j!nT e ¡j!¿ ´<br />
¡ e<br />
j!nT<br />
1<br />
j!¿<br />
= Xs(!)e ¡1 2j!¿ ej 1 2 !¿ ¡ e ¡j 1 2 !¿<br />
2j 1 2 !¿<br />
= Xs(!)e ¡j 1 2 !¿ sin ³ 1<br />
2 !¿ ´<br />
³<br />
´<br />
1 ¡ e<br />
¡j!¿<br />
ideal sampling X S() impact of hold<br />
1<br />
2 !¿<br />
32
Representation of Discrete Time <strong>Signal</strong>s and<br />
Spectral Transformation<br />
Henzler, Schmitt-Landsiedel <strong>Mixed</strong>-<strong>Signal</strong>-<strong>Electronics</strong> 2011/12<br />
33