Pll Basic

4,149 views
3,947 views

Published on

Published in: Technology, Business
1 Comment
1 Like
Statistics
Notes
No Downloads
Views
Total views
4,149
On SlideShare
0
From Embeds
0
Number of Embeds
50
Actions
Shares
0
Downloads
169
Comments
1
Likes
1
Embeds 0
No embeds

No notes for slide

Pll Basic

  1. 1. Goldman Research PLL Basics 2-28-2009 Stan Goldman Goldman Research Goldman Research 5/3/2009 Page 1
  2. 2. Goldman Research PLL Basics Agenda • History • Applications • Overview of PLLs • Background information • Control Systems • Test and Measurement • References and Background Material Goldman Research 5/3/2009 Page 2
  3. 3. Goldman Research History • De Bellescize in 1932 – Synchronous reception of radio signals – Received audio amplified to speaker • Television, 1st wide spread use – Synchronization of horizontal and vertical scan in television Goldman Research 5/3/2009 Page 3
  4. 4. Goldman Research Applications • Frequency multiplier by multiplying the frequency of the reference oscillator. • Modulator by adding the modulating signal to the phase error. • Demodulator by tracking the changes in modulation to the reference input. • Coherent receiver by operating as a narrow band tunable filter to track the carrier frequency. • Data synchronizer by operating as a narrow band tunable filter to recover the clock. Goldman Research 5/3/2009 Page 4
  5. 5. Goldman Research Serializer/Deserializer Goldman Research 5/3/2009 Page 5
  6. 6. Goldman Research Hard Disk Drive Goldman Research 5/3/2009 Page 6
  7. 7. Goldman Research Wireless CELL PHONE Goldman Research 5/3/2009 Page 7
  8. 8. Goldman Research KEY PLL DESIGN REQUIREMENTS • Architecture • Loop Stability • Frequency Range • Time Jitter Goldman Research 5/3/2009 Page 8
  9. 9. Goldman Research PLL Control System Block Diagram With Phase Relationships θo θi θi θ0 n mf [Goldman 2007 p19] Goldman Research 5/3/2009 Page 9
  10. 10. Goldman Research Key Signals of Interest within a PLL • Input frequency or reference frequency • Output frequency • Tune voltage or current input to the VCO or CCO • Phase error (comparison of the positive edge of the reference input signal to the phase detector with the positive edge of the feed back signal from the VCO to the phase detector with the positive edge of the reference input as the trigger source) Goldman Research 5/3/2009 Page 10
  11. 11. Goldman Research Ideal VCO Transfer Function, Transduces Voltage to Frequency (Edges) ωout=ωoff+Kv Vtune ωout=∆θout/∆t 1 E9 8 E8 To = 2 M Td 4 E8 0 [Goldman 2007 p3] Goldman Research 5/3/2009 Page 11
  12. 12. Goldman Research Relationship of Phase/Frequency in VCO, (1/s transfer function relationship) • Mathematical description of a phase modulated signal, from Taub and Shilling, Principles of Communication Systems, p117 and modified with PLL terminology:    ω ⋅ t + K ⋅ ⌠ V ( t ) dt  V o( t ) V a⋅ cos c  v tune ⌡     ⌠ d  V ( t ) dt ω ω c⋅ t + K v⋅ ω c + K v⋅ V tune( t ) dt   tune Instantaneous Frequency ⌡   ω − ωc⋅ t Kv⋅ Vtune( t) Deviation of instantaneous frequency fo from wc which equals wref in modeling 2⋅ π 2⋅ π ⌠ ω c⋅ t + K v⋅  V tune( t ) dt Instantaneous phase θ  oi ⌡ Deviation of instantaneous phase ⌠ K v⋅  V tune( t) dt 1 θ θ − ω c⋅ t K v⋅ ⋅ V tune( s )  o ⌡ s Goldman Research 5/3/2009 Page 12
  13. 13. Goldman Research Digital Phase Detector Timing and Response to Ramped VCO Phase UP VDD D Q RIN C Q CL DOWN VDD D Q VCOIN C Q CL Reset Goldman Research 5/3/2009 Page 13
  14. 14. Goldman Research Ideal Phase Detector Transfer Function, Transduces Frequency (Edge) Differences to Voltage Vpdavg=Kd θe (5MHz Ref. Freq.) -100 0 100 200 -200 Ref. – VCO Edge (ns) [Goldman 2007 p2] Goldman Research 5/3/2009 Page 14
  15. 15. Goldman Research Output of Analog Phase Detector vs Phase Error (-cos) with Various Measures of Abscissa [Goldman 2007 p18] Goldman Research 5/3/2009 Page 15
  16. 16. Goldman Research Example of Lock, Digital Loop (In Phase) [Goldman 2007 p4] Goldman Research 5/3/2009 Page 16
  17. 17. Goldman Research Mathematical Relationship of Phase and Frequency (Analog Phase Detector) Phase detector as a mixer (analog multiplier) Signal Definition Mixing of Two Signals V1(t)= Vp1 cos(ωrft+ θe ) V1(t) V2(t) = Vp1Vp2 cos(ωrf t + θe ) cos(ωlo t ) where: V1(t)= Source 1 signal, Using the trigonometric identity for products of a trigonometric function: Vp1= Maximum amplitude of source 1 (volts), ωrf= Angular frequency of a Signal at the RF port of the mixer (rad./sec), V1(t) V2(t)=Vp1Vp2 0.5 [cos ( ωrf t- ωlo t + θe ) +cos( ωrf t + ωlo t + θe )] = 2 π frf, θe= Phase error difference between signal 1 and 2 (rad.), and where: t= Time variable (seconds). V1(t) V2(t) = Mixing process. V2(t) = Vp2 cos(ωlo t ) Eliminating the high frequency product where: with a low pass filter yields V2(t)= Source 2 signal, Vp2= Maximum amplitude of source 2 (volts), and ωlo= Angular frequency of a signal at the LO port of a mixer (rad./sec). V1(t) V2(t) =Vp1 Vp2 0.5 [ cos(ωrf t - ωlo t + θe ) ] =Vpbeat cos( ωbeat t + θe ) where: ωbeat = ωrf - ωlo for ωrf > ωlo, Vpbeat = Vp1 Vp2 x 0.5 x mixer losses, and = The resulting voltage level after mixing (volts). Slope () () d V pbeat ⋅cos θ e V pbeat ⋅sin θ e V pds dθ e where: Phase Detector Gain Vpds ( φ)= Phase detector phase slope (volts). Kd=Vpbeat Vpds(θe) = Vpbeat sin(θe ) Goldman Research 5/3/2009 Page 17
  18. 18. Goldman Research Charge Pump Output Transduces Frequency (Edge) Differences to Current, Kp=I/(2 π) Goldman Research 5/3/2009 Page 18
  19. 19. Goldman Research Loop Classifications [Goldman 2007 p8] Goldman Research 5/3/2009 Page 19
  20. 20. Goldman Research Loop Classifications (Continued) [Goldman 2007 p8] Goldman Research 5/3/2009 Page 20
  21. 21. Goldman Research Example of Lock, Analog Loop (Sinewaves) Phase detector as a mixer (analog multiplier) VCO Tune Voltage Goldman Research 5/3/2009 Page 21
  22. 22. Goldman Research Vtune, Input, and Output Signals, Locked (Quadrature) Goldman Research 5/3/2009 Page 22
  23. 23. Goldman Research Vtune, Input, and Output Signals, During Acquisition, Searching For Lock In phase for higher tune voltage Out of phase for lower tune voltage Goldman Research 5/3/2009 Page 23
  24. 24. Goldman Research PLL TRANSFER FUNCTION AND CONTROL SYSTEMS THEORY • Control System's General Equation for a Closed Loop Co G (s) = Ri 1 ± G ( s ) ⋅ H ( s ) - =For positive feedback, + =For negative feedback, Co R i =The closed-loop transfer function, G(s)=Forward transfer function, H(s)=Feedback transfer function, G(s) H(s)=Open-loop transfer function, and G(s) H(s)=Ratio of 1 and angle of 0 deg for positive feedback and 180 deg for negative feedback are the conditions for oscillation. • Closed Loop PLL Transfer Function from General Equation θo G( s ) (s) θi G( s ) . H ( s ) 1 θ0 =Output phase (rad) and θi =Input phase (rad). Goldman Research 5/3/2009 Page 24
  25. 25. Goldman Research Judging Stability from Step Response Freqeuncy (Hz) 4 6 10 .035 Damping 3 10 4 4 deg. Phase Margin ~90% Overshoot 0 4 10 6 .2 Damping 3 10 4 22 deg. Phase Margin ~60% Overshoot 0 6 10 4 .42 Damping 4 3 10 45 deg. Phase Margin ~40% Overshoot 0 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.01 0.009 Time (s) [Goldman 2007 p20] 30 deg or 45 deg. Phase Margin are levels supported in references Goldman Research 5/3/2009 Page 25
  26. 26. Goldman Research PLL Basic Block Diagram For Cascade of Transfer functions for Open Loop Gain [Goldman 2007 p22] Goldman Research 5/3/2009 Page 26
  27. 27. Goldman Research Type 2 Second Order Open Loop Gain Function (Active Filter) Cascade of Transfer functions for Open Loop Gain G(s)H(s)= (Phase Detector Gain)(Filter Transfer Function) (VCO Transfer Function)(Divider Transfer Function) Substitute and Rearrange for Open Loop Gain Expression K d. K v . 1 . s . C. R G( s ) . H ( s ) 1 2 n mf . C . R 1 s 2 Substitute and Rearrange for Closed Loop Gain Expression Kd = Phase detector gain (volts/radian), = Capacitor in the operational amplifier's C = VCO transfer function gain feedback path (F), Kv constant (radians/second/volt), = Resistor in operational amplifier's R1 = Integer divider value, feedback path (ohms) and, n mf = Loop Frequency Multiplication Factor, = Resistor at the negative input terminal = Output frequency/ input frequency, of the operational amplifier (ohms). R2 Goldman Research 5/3/2009 Page 27
  28. 28. Goldman Research Converting to Servo Terminology Closed Loop Gain Expression . s. 2 ζ . 2 n mf . ω n 1 ωn G( s ) G( s ) . H ( s ) 1 2 2 s . 2 . ζω ωn s n Error Expression 2 1 s G( s ) . H ( s ) 1 2 2 s . 2 . ζω ωn s n Open loop gain Expression . s.2 ζ . 1 2 ωn G( s ) . H ( s ) . 1 ωn 2 s Goldman Research 5/3/2009 Page 28
  29. 29. Goldman Research Synthesis of loop component values from servo terminology R2. C Kd. Kv Kd. Kv ζ . ωn R1. C. nmf 2 R1. C. n mf • Active Filter For selected C value, damping factor, and natural frequency and given Kd and Kv Kd.Kv 2. ζ R1 R2 ω .C 2 ω n .C.nmf n • Passive Filter Kd. Kv Kd.Kv 1. 1 ωn ζ . R .C R2 . C. n mf 2 R1 R2 .Cnmf 2 R1 . Kd.Kv K v . Ip . R 2 K v . Ip • Charge Pump 2 . π . n mf ωn ζ 2. π . C. n mf 2.ω n Goldman Research 5/3/2009 Page 29
  30. 30. Goldman Research Charge Pump PLL with Regulator •Charge pump can not drive high current load •1 pin for external components Goldman Research 5/3/2009 Page 30
  31. 31. Goldman Research Loop Stability, Bode Plot Magnitude Phase Margin Phase Gain Margin [Goldman 2007 p27] Goldman Research 5/3/2009 Page 31
  32. 32. Goldman Research Graphical Relationship of Natural Frequency to 0 dB Crossover Frequency [Goldman 2007 p29] Goldman Research 5/3/2009 Page 32
  33. 33. Goldman Research Open Loop Response (ASIC APLL External Components ) 32, 71, 147 MHz 71 MHz 32 MHz 147 MHz 147 MHz 32 MHz 71 MHz Goldman Research 5/3/2009 Page 33
  34. 34. Goldman Research Closed Loop Response (APLL) 32 MHz 71 MHz 147 MHz Goldman Research 5/3/2009 Page 34
  35. 35. Goldman Research Error Function Response Goldman Research 5/3/2009 Page 35
  36. 36. Goldman Research Test and Measurement of PLL (Brief) • Spurious signals, hold in range, and lock range • Frequency Switching Time • Jitter Goldman Research 5/3/2009 Page 36
  37. 37. Goldman Research Spurious Signals [Goldman 2007 p357] Goldman Research 5/3/2009 Page 37
  38. 38. Goldman Research Hold In Range, Lock In Range [Goldman 2007 p355] Goldman Research 5/3/2009 Page 38
  39. 39. Goldman Research Jitter Measurements • Oscilloscope (Time Domain) • Modulation Domain Analyzer • Spectrum Analyzer ( Frequency Domain) Goldman Research 5/3/2009 Page 39
  40. 40. Goldman Research Jitter, Oscilloscope [Goldman 2007 p388] Goldman Research 5/3/2009 Page 40
  41. 41. Goldman Research Relationship of Modulation Domain to Spectrum Analyzer and Oscilloscope F T V [Goldman 2007 p378] Goldman Research 5/3/2009 Page 41
  42. 42. Goldman Research Oscilloscope Measurement of 1 and Multiple Periods 1 clo ck p eriod oscilloscop e m easurem ent w ith jitter FM m odulation 1 p eriod scope m easurem ent 1 T 1 6 clock periods o scilloscope m easurem ent w ith jitter F M m odulation 6 th period scop e m easurem ent 1 T 1 [Goldman 2007 p380] Goldman Research 5/3/2009 Page 42
  43. 43. Goldman Research Frequency Switching Time, Modulation Domain Analyzer [Goldman 2007 p358] Goldman Research 5/3/2009 Page 43
  44. 44. Goldman Research Comparison Table of Measured Data with Comparable PLL References power supply Area VCO Output sensitivity, %- Description Processes Power (mm2) Frequency (MHz) Jitter fvco/%-Vdd Comments Simulated, Supply S. Sidropoulos Controlled Ring VCO, VLSI '00 .35um 3.3V 21.5mW@500MHz 0.047 30-650 .06%/1% wide BW J.M. Ingino ISSCC 44ps p-p at Regulator included, '01 .15um 3.3V 132mW@4GHz 1.48 600- 4000 700MHz .007%/1% single ended ring CCO Supply Controled Ring VCO, wide BW, 2.5MHZ H. Ahn JSSC '00 .25um 1.9V 25mW@320MHz 0.087 17-1320 0.32%/1% BW K. Minami CICC '01 .1um 1.2V 30mW at 2000MHz 0.15 500-2350 21ps p-p Single ended ring CCO Maneatis ISSCC Differential ring VCO, '03 .13um 1.5V 7mW at 240MHz 0.18 30-650 48ps p-p self biased Differential ring VCO, Hozer ISSCC '02 .13um 1.5V 7mW at 200MHz 0.16 10-350 155ps p-p 360MHz VCR All Digital PLL, diff. ring Fahim TCAS '03 .25um 1.9V 3.12mW at 160MHz 30-160 130ps p-p VCO DCAS 2008 .065um 1.2V 1mW at 240MHz 0.06 12-600 80ps p-p 0.02%/1% Goldman Research 5/3/2009 Page 44
  45. 45. Goldman Research Recommended PLL Books 1. Stanley Goldman, Phase Locked Loop Engineering Handbook, Artech House, Boston, 2007. 2. Roland Best, Phase Locked Loops Design Simulation, & Applications, McGraw Hill, New York, 1997. 3. Behzad Razavi, Monolithic Phase-Locked Loops and Clock Recovery Circuits, EEE Press, New York 1996. 4. James A. Crawford, Frequency Synthesizer Design Handbook, Artech House, Boston. 5. William Egan, Frequency Synthesis by Phase-Lock, Wiley Interscience, New York, 1981. 6. Floyd Martin Gardner, Phaselock Techniques, Wiley Interscience, New York, 1979. Goldman Research 5/3/2009 Page 45
  46. 46. Goldman Research Recommended Background Books Feedback Control Systems by Charles L. Phillips and Royce D. Harbor The Fast Fourier Transform by E. Oran Brigham Network Analysis by Van Valkenburg Analysis and Design of Analog Integrated Circuits by Paul R. Gray and Robert G. Meyer Principles of CMOS VLSI Design by Neil H. E. Weste and Kamran Eshraghian Principles of Communicaton Systems by H. Taub and D. L. Schilling Goldman Research 5/3/2009 Page 46
  47. 47. Goldman Research External Websites • Texas Instruments, High Performance PLLs http://www.ti.com/sc/docs/products/msp/clock/pll/overview.htm • National Semiconductor http://www.national.com/appinfo/wireless/ • Frequency Response Analysis and Design Tutorials http://me.www.ecn.purdue.edu/~me475/ctm/freq/freq.html • Chip Directory http://icat.snu.ac.kr/chipdir/f/pll.htm • Phase Locked Loop Fundamentals ( Minicircuits) http://www.minicircuits.com/appnote/vco15-10.pdf • Monolithic CMOS RF Transceiver (Berkeley) http://kabuki.eecs.berkeley.edu/rf/rf.html • Analog IC Design, Dr Hellums (UTD) http://www.utdallas.edu/~hellums/ • PLLs , Stan Goldman http://home.tx.rr.com/sgold_1 Goldman Research 5/3/2009 Page 47

×