Structured Electronic Design. ET ECTS credits

Transcription

1 Structured Electronic Design ET ECTS credits

2 Some keywords: Structured Electronic Design Design methodology Analysis and Synthesis Applied network theory Fundamental research Free-swinging intellect 2

3 An amplifier 0kΩ. What type of amplifier is this? 2. When the gain is 0, what is the value of? 3

4 Another amplifier 0kΩ 2 3. When the gain is 00, what is the value of 2? 4

5 And another amplifier 0kΩ 3 4. When the gain is 2, what is the value of 3? 5

6 And another 0kΩ 4 5. When the gain is 20, what is the value of 4? 6

7 6. How do you get the crab out? 7

8 8

9 Fundamental research How to design an amplifier? (techniques) Why do it this way? (philosophy) 9

10 0

11 r b c μ rπ cπ r o 7. What is this?

12 8. Will the lamp light up? 2

13 9. Will the lamp light up? 3

14 YES NO 4

15 Platonic solids Tetrahedron Hexahedron Octahedron Edges Edges and and angles angles are are all all congruent Dodecahedron Icosahedron 5

16 6

17 0.Is this a good model? It correctly predicts the orbit of all planets you can see with the naked eye. 7

18 Modeling A correct model gives a correct prediction 8

19 Platonic solids The The Tetrahedron five five Pythagorean regular Hexahedron polyhedra dictate the the structure Octahedron of of the the universe and and reflect God's plan plan through geometry ; June9, 595, Johannes Kepler Dodecahedron Icosahedron 9

20 Modeling A correct model gives a correct prediction Never confuse models with the truth 20

21 Back to the amplifier 0kΩ 0kΩ V kω Kirchoffs first law is is not obeyed! 6. What is the current through the load? 2

22 Design problems arise from bad formulations udwig Wittgenstein(889-95) anguage is is a labyrinth of of paths 22

23 Amplifier design 23

24 An amplifier with a nullor 0kΩ

25 Nullor i in =0 i out v in =0 v out Input Input current current and and input input voltage voltage of of the the nullor nullor are are made made zero zeroby by the the output output signals signals of of the the nullor nullor 25

26 Inside the Nullor i = 0 i = 0? v = 0? i = 0! v = 0! v = 0 Nullator Norrator Nullator Norrator Input Input current current and and input input voltage voltage of of the the nullor nullor are are made made zero zeroby by the the output output signals signals of of the the nullor nullor 26

27 What is is the transfer T of this amplifier? 2 27

28 The transfer T of this amplifier 2 T = 2 v out 28

29 Another transfer T of this amplifier 2 Tanother = 2 i in v out 29

30 Joseph Henry The seeds of great discovery are constantly floating around us, but they only take root in minds well prepared to receive them 30

31 The chain matrix of this amplifier T 2 2 = Tanother = 2 T again another =? 0 v v in 2 out = i i in 0 out 2?? 3

32 The two-port and its chain matrix i in + + i out v in v out v i in in = A C B D v i out out 32

33 The two-port and its chain matrix i in i out v in + + v out v i in in = A C B D v i out out v A = in v = out i out 0 v B = in i = out v out 0 i C = in v = out i out i D = in i 0 out v = 0 out 33

34 Nullor i in =0 + _ i out v in =0 v out _ + Input current and input voltage of the nullor are made zero via the output signals of the nullor v A0 0B v in out = i C0 0D i in out 34

35 Accurate amplification Information from source to load Signal power is enlarged Information stays unaltered A C B D A,B,C,D constant A,B,C,D accurately known 35

36 A voltage-to-voltage amplifier v in v out A v = 2 36

37 2 s v in v out A v = + 2 s Amplification factor becomes inaccurate. 37

38 2 s v in Optimization v out v n 2 Av = + s S = 4 kt + // v n ( ) s 2 Information is disturbed Amplification factor still inaccurate. 38

39 Change topology 2 Orthogonalization vin s + 2 Av = S = 4 kt( + // ) v n s 2 v out 39

40 2 v out v in s A v 2 S = 4 kt( + // ) i v fb n = = + vout + 2 s 2 40

41 Orthogonalization 2 v out v in s Optimization 2 s v in v out 4

42 n v out v in s A S i v v fb n = n = = 0 4kT s A v 2 S = 4 kt( + // ) i v fb n = = + vout + 2 s 2 42

43 ight choice Orthogonalization Optimization 43

44 The right choice: Start? (as usual?) Analyze? Optimize? Orthogonality? Specifications? Criteria? 44

45 The criteria C = B 2 log S + N N. Noise 2. Signal power (distortion) 3. Bandwidth And what about supply voltage, current, power consumption, technology etc.? 45

46 Correlated properties Optimization.. Noise Signal power (distortion) Bandwidth Orthogonalization 46

47 Orthogonal properties (2) Properties are generally not orthogonal But designas if Make it right 47

48 As if When optimizing bandwidth: Small-signal models (no non-linearity) No noise When optimizing noise behavior: Small-signal models (no non-linearity) No bandwidth details When optimizing non-linear behavior (distortion): No dynamic effects No noise 48

49 The most orthogonal sequence? bandwidth noise distortion bandwidth distortion - noise noise - bandwidth distortion noise distortion - bandwidth distortion - noise bandwidth distortion bandwidth - noise 49

50 Know which problem to solve first Is it a cow? Is it green? Is it an animal? 50

51 See the structure: Create Hierarchy! Global Detail V hoog imiter Memory Σ V c imiter V laag 5

52 Efficient design The right design step at the right time A design step occurs only once Orthogonality, hierarchy, classification 52

53 Efficient design (2) educe the search space as fast as possible. ook for fast criteria: Necessary but not sufficient (e.g. P -product) Extensive calculations only when it makes sense Simplest model that suffices 53

54 Attitude Know exactly what you want Use second best, if you can t have it Know the penalty 54

55 Voltage amplifier, what s in the nullor? Nullor Source oad 55

56 Inside the Nullor Nullator Norrator 56

57 Nullator? Norrator? i = 0 Current sensor Current source v = 0 Nullator Norrator Voltage sensor Voltage source 57

58 practical nullor implementations v A v B i C i D 58

59 Choose Nullor Source oad v A v B i C i D 59

60 The experts with practical experience v 60

61 6 oopgain with B-type block oopgain with B-type block Source v oad 2 C 2 B j C j C ω ω + = + + +

62 62 oopgain with A-type block oopgain with A-type block 2 v Source oad C 2 A = + 2 B j C j C ω ω + = + + +

63 Which transistor stage? v Source 2 oad C CE-stage CB-stage CC-stage Differential CE-stage Differential CB-stage Differential CC-stage 63

64 Voltage amplifier with A-type block Source v 2 oad C = < A + 2 Source 2 oad C 64

65 65 Back to the B-type solution (told you so.) Back to the B-type solution (told you so.) 2 Source oad C 2 2 E C j C j B C ω ω = >

66 The expert solution 2r o = ACEACC + 2 Source r o should be be low??? low??? ( + 2) + jωc jωc + ( + 2) + jωc 2roD CC jωc 2 lim = r o Miller effect Distortion oad C + jωc 2BCE D CC jωc A CE = B CE r o 2 66

67 Expert versus logic 2r o Source = ACEACC oad miller effect first first stage distortion and and clipping first first stage oopgain not(less) load load dependent C ( + 2) + jωc jωc + ( + 2) + jωc 2roD CC jωc Source = 2B D CE CC 2 + oad + jωc + + jω C 2 C no no miller effect less less distortion oad dependent loopgain 67

68 Which solution when? 2r o Source 2 oad C Source 2 oad C miller effect first first stage distortion and and clipping first first stage oopgain not(less) load load dependent no no miller effect less less distortion oad dependent loopgain 68

69 Alternatives 69

70 Know ideal case Conclusions 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 70