JAJSE94B december   2017  – august 2023 LMK61E07

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics - Power Supply
    6. 6.6  LVPECL Output Characteristics
    7. 6.7  LVDS Output Characteristics
    8. 6.8  HCSL Output Characteristics
    9. 6.9  Frequency Tolerance Characteristics
    10. 6.10 Frequency Margining Characteristics
    11. 6.11 Power-On Reset Characteristics (VDD)
    12. 6.12 I2C-Compatible Interface Characteristics (SDA, SCL)
    13. 6.13 PSRR Characteristics
    14. 6.14 Other Characteristics
    15. 6.15 PLL Clock Output Jitter Characteristics
    16. 6.16 Typical 156.25-MHz Output Phase Noise Characteristics
    17. 6.17 Typical 161.1328125 MHz Output Phase Noise Characteristics
    18. 6.18 Additional Reliability and Qualification
    19. 6.19 Typical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Device Output Configurations
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Device Block-Level Description
      2. 8.3.2  Device Configuration Control
      3. 8.3.3  Register File Reference Convention
      4. 8.3.4  Configuring the PLL
      5. 8.3.5  Integrated Oscillator
      6. 8.3.6  Reference Divider and Doubler
      7. 8.3.7  Phase Frequency Detector
      8. 8.3.8  Feedback Divider (N)
      9. 8.3.9  Fractional Engine
      10. 8.3.10 Charge Pump
      11. 8.3.11 Loop Filter
      12. 8.3.12 VCO Calibration
      13. 8.3.13 High-Speed Output Divider
      14. 8.3.14 High-Speed Clock Output
      15. 8.3.15 Device Status
        1. 8.3.15.1 Loss of Lock
    4. 8.4 Device Functional Modes
      1. 8.4.1 Interface and Control
      2. 8.4.2 DCXO Mode and Frequency Margining
        1. 8.4.2.1 DCXO Mode
        2. 8.4.2.2 Fine Frequency Margining
        3. 8.4.2.3 Coarse Frequency Margining
    5. 8.5 Programming
      1. 8.5.1 I2C Serial Interface
      2. 8.5.2 Block Register Write
      3. 8.5.3 Block Register Read
      4. 8.5.4 Write SRAM
      5. 8.5.5 Write EEPROM
      6. 8.5.6 Read SRAM
      7. 8.5.7 Read EEPROM
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
        1. 8.6.1.1  VNDRID_BY1 Register; R0
        2. 8.6.1.2  VNDRID_BY0 Register; R1
        3. 8.6.1.3  PRODID Register; R2
        4. 8.6.1.4  REVID Register; R3
        5. 8.6.1.5  TARGETADR Register; R8
        6. 8.6.1.6  EEREV Register; R9
        7. 8.6.1.7  DEV_CTL Register; R10
        8. 8.6.1.8  XO_CAPCTRL_BY1 Register; R16
        9. 8.6.1.9  XO_CAPCTRL_BY0 Register; R17
        10. 8.6.1.10 DIFFCTL Register; R21
        11. 8.6.1.11 OUTDIV_BY1 Register; R22
        12. 8.6.1.12 OUTDIV_BY0 Register; R23
        13. 8.6.1.13 RDIVCMOSCTL Register; R24
        14. 8.6.1.14 PLL_NDIV_BY1 Register; R25
        15. 8.6.1.15 PLL_NDIV_BY0 Register; R26
        16. 8.6.1.16 PLL_FRACNUM_BY2 Register; R27
        17. 8.6.1.17 PLL_FRACNUM_BY1 Register; R28
        18. 8.6.1.18 PLL_FRACNUM_BY0 Register; R29
        19. 8.6.1.19 PLL_FRACDEN_BY2 Register; R30
        20. 8.6.1.20 PLL_FRACDEN_BY1 Register; R31
        21. 8.6.1.21 PLL_FRACDEN_BY0 Register; R32
        22. 8.6.1.22 PLL_MASHCTRL Register; R33
        23. 8.6.1.23 PLL_CTRL0 Register; R34
        24. 8.6.1.24 PLL_CTRL1 Register; R35
        25. 8.6.1.25 PLL_LF_R2 Register; R36
        26. 8.6.1.26 PLL_LF_C1 Register; R37
        27. 8.6.1.27 PLL_LF_R3 Register; R38
        28. 8.6.1.28 PLL_LF_C3 Register; R39
        29. 8.6.1.29 PLL_CALCTRL Register; R42
        30. 8.6.1.30 NVMSCRC Register; R47
        31. 8.6.1.31 NVMCNT Register; R48
        32. 8.6.1.32 NVMCTL Register; R49
        33. 8.6.1.33 NVMLCRC Register; R50
        34. 8.6.1.34 MEMADR Register; R51
        35. 8.6.1.35 NVMDAT Register; R52
        36. 8.6.1.36 RAMDAT Register; R53
        37. 8.6.1.37 NVMUNLK Register; R56
        38. 8.6.1.38 INT_LIVE Register; R66
        39. 8.6.1.39 SWRST Register; R72
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 PLL Loop Filter Design
        2. 9.2.2.2 Spur Mitigation Techniques
          1. 9.2.2.2.1 Phase Detection Spur
          2. 9.2.2.2.2 Integer Boundary Fractional Spur
          3. 9.2.2.2.3 Primary Fractional Spur
          4. 9.2.2.2.4 Sub-Fractional Spur
        3. 9.2.2.3 Device Programming
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Ensured Thermal Reliability
        2. 9.4.1.2 Best Practices for Signal Integrity
        3. 9.4.1.3 Recommended Solder Reflow Profile
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Mechanical, Packaging, and Orderable Information
9.2.2.2.4 Sub-Fractional Spur

These spurs appear at a fraction of fPD/DEN and depend on modulator order. With the first order modulator, there are no sub-fractional spurs. The second order modulator can produce 1/2 sub-fractional spurs if the denominator is even. A third order modulator can produce sub-fractional spurs at 1/2, 1/3, or 1/6 of the offset, depending if it is divisible by 2 or 3. For instance, if the phase detector frequency is 100 MHz and the fraction is 3/100, no sub-fractional spurs for a first order modulator or sub-fractional spurs at multiples of 1.5 MHz for a second or third order modulator would be expected. Aside from strategically choosing the fractional denominator and using a lower order modulator, another tactic to eliminate these spurs is to use dithering and express the fraction in larger equivalent terms. Because dithering also adds phase noise, its level needs to be managed to achieve acceptable phase noise and spurious performance.

Table 9-2 summarizes spur and mitigation techniques.

Table 9-2 Spur and Mitigation Techniques
SPUR TYPEOFFSETWAYS TO REDUCETRADE-OFFS
Phase DetectorfPDReduce Phase Detector Frequency.Although reducing the phase detector frequency does improve this spur, it also degrades phase noise.
Integer BoundaryfVCO mod fPDMethods for PLL Dominated SpursReducing the loop bandwidth may degrade the total integrated noise if the bandwidth is too narrow.
-     Avoid the worst case VCO frequencies if possible.
-     Ensure good slew rate and signal integrity at reference input.
-     Reduce loop bandwidth or add more filter poles to suppress out of band spurs.
Methods for VCO Dominated SpursReducing the phase detector may degrade the phase noise.
-     Avoid the worst case VCO frequencies if possible.
-     Reduce Phase Detector Frequency.
-     Ensure good slew rate and signal integrity at reference input.
Primary FractionalfPD/DEN-     Decrease Loop Bandwidth.Decreasing the loop bandwidth may degrade in-band phase noise. Also, larger unequivalent fractions don’t always reduce spurs.
-     Change Modulator Order.
-     Use Larger Unequivalent Fractions.
Sub-FractionalfPD/DEN/k k=2,3, or 6-     Use Dithering.Dithering and larger fractions may increase phase noise.
-     Use Larger Equivalent Fractions.
-     Use Larger Unequivalent Fractions.
-     Reduce Modulator Order.
-     Eliminate factors of 2 or 3 in denominator.