ZHCSFZ0D December   2016  – December 2023 DAC38RF80 , DAC38RF83 , DAC38RF84 , DAC38RF85 , DAC38RF90 , DAC38RF93

PRODUCTION DATA  

  1.   1
  2. 特性
  3. 应用
  4. 说明
  5. Device Comparison
  6. Pin Configuration and Functions
  7. 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 - DC Specifications
    6. 6.6  Electrical Characteristics - Digital Specifications
    7. 6.7  Electrical Characteristics - AC Specifications
    8. 6.8  PLL/VCO Electrical Characteristics
    9. 6.9  Timing Requirements
    10. 6.10 Typical Characteristics
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1  SerDes Inputs
      2. 7.3.2  SerDes Rate
      3. 7.3.3  SerDes PLL
      4. 7.3.4  SerDes Equalizer
      5. 7.3.5  JESD204B Descrambler
      6. 7.3.6  JESD204B Frame Assembly
      7. 7.3.7  SYNC Interface
      8. 7.3.8  Single or Dual Link Configuration
      9. 7.3.9  Multi-Device Synchronization
      10. 7.3.10 SYSREF Capture Circuit
      11. 7.3.11 SerDes Test Modes through Serial Programming
      12. 7.3.12 SerDes Test Modes through IEEE 1500 Programming
      13. 7.3.13 Error Counter
      14. 7.3.14 Eye Scan
      15. 7.3.15 JESD204B Pattern Test
      16. 7.3.16 Multiband DUC (multi-DUC)
        1. 7.3.16.1 Multi-DUC input
        2. 7.3.16.2 Interpolation Filters
        3. 7.3.16.3 JESD204B Modes, Interpolation and Clock phase Programming
        4. 7.3.16.4 Digital Quadrature Modulator
        5. 7.3.16.5 Low Power Coarse Resolution Mixing Modes
        6. 7.3.16.6 Inverse Sinc Filter
        7. 7.3.16.7 Summation Block for Dual DUC Modes
      17. 7.3.17 PA Protection Block
      18. 7.3.18 Gain Block
      19. 7.3.19 Output Summation
      20. 7.3.20 Output Delay
      21. 7.3.21 Polarity Inversion
      22. 7.3.22 Temperature Sensor
      23. 7.3.23 Alarm Monitoring
      24. 7.3.24 Differential Clock Inputs
      25. 7.3.25 CMOS Digital Inputs
      26. 7.3.26 DAC Fullscale Output Current
      27. 7.3.27 Current Steering DAC Architecture
      28. 7.3.28 DAC Transfer Function for DAC38RF83, 93, 85
      29. 7.3.29 DAC Transfer Function for DAC38RF80/90/84
    4. 7.4 Device Functional Modes
      1. 7.4.1 Clocking Modes
      2. 7.4.2 PLL Bypass Mode Programming
      3. 7.4.3 Internal PLL/VCO
      4. 7.4.4 CLKOUT
      5. 7.4.5 Serial Peripheral Interface (SPI)
        1. 7.4.5.1 NORMAL (RW)
        2. 7.4.5.2 WRITE_TO_CLEAR (W0C)
        3. 7.4.5.3 Writing to Reserved Bits
    5. 7.5 Register Maps
      1. 7.5.1  Chip Reset and Configuration Register (address = 0x00) [reset = 0x5803]
      2. 7.5.2  IO Configuration Register (address = 0x01) [reset = 0x1800]
      3. 7.5.3  Lane Single Detect Alarm Mask Register (address = 0x02) [reset = 0xFFFF]
      4. 7.5.4  Clock Alarms Mask Register (address = 0x03) [reset = 0xFFFF
      5. 7.5.5  SERDES Loss of Signal Detection Alarms Register (address = 0x04) [reset = 0x0000]
      6. 7.5.6  SYSREF Alignment Circuit Alarms Register (address = 0x05) [reset = variable]
      7. 7.5.7  Temperature Sensor and PLL Loop Voltage Register (address = 0x06) [reset = variable]
      8. 7.5.8  Page Set Register (address = 0x09) [reset = 0x0000]
      9. 7.5.9  SYSREF Align to r1 and r3 Count Register (address = 0x78) [reset = 0x0000]
      10. 7.5.10 SYSREF Phase Count 1 and 2 Register (address = 0x79) [reset = 0x0000]
      11. 7.5.11 SYSREF Phase Count 3 and 4 Register (address = 0x7A) [reset = 0x0000]
      12. 7.5.12 Vendor ID and Chip Version Register (address = 0x7F) [reset = 0x0009]
      13. 7.5.13 Multi-DUC Configuration (PAP, Interpolation) Register (address = 0x0A) [reset = 0x02B0]
      14. 7.5.14 Multi-DUC Configuration (Mixers) Register (address = 0x0C) [reset = 0x2402]
      15. 7.5.15 JESD FIFO Control Register (address = 0x0D)[reset = 0x8000]
      16. 7.5.16 Alarm Mask 1 Register (address = 0x0E) [reset = 0x00FF]
      17. 7.5.17 Alarm Mask 2 Register (address = 0x0F) [reset = 0xFFFF]
      18. 7.5.18 Alarm Mask 3 Register (address = 0x10) [reset = 0xFFFF]
      19. 7.5.19 Alarm Mask 4 Register (address = 0x11) [reset = 0xFFFF]
      20. 7.5.20 JESD Lane Skew Register (address = 0x12) [reset = 0x0000]
      21. 7.5.21 CMIX Configuration Register (address = 0x17) [reset = 0x0000]
      22. 7.5.22 Output Summation and Delay Register (address = 0x19) [reset = 0x0000]
      23. 7.5.23 NCO Phase Path AB Register (address = 0x1C) [reset = 0x0000]
      24. 7.5.24 NCO Phase Path CD Register (address = 0x1D) [reset = 0x0000]
      25. 7.5.25 NCO Frequency Path AB Register (address = 0x1E-0x20) [reset = 0x0000 0000 0000]
      26. 7.5.26 NCO Frequency Path CD Register (address = 0x21-0x23) [reset = 0x0000 0000 0000]
      27. 7.5.27 SYSREF Use for Clock Divider Register (address = 0x24) [reset = 0x0010]
      28. 7.5.28 Serdes Clock Control Register (address = 0x25) [reset = 0x7700]
      29. 7.5.29 Sync Source Control 1 Register (address = 0x27) [reset = 0x1144]
      30. 7.5.30 Sync Source Control 2 Register (address = 0x28) [reset = 0x0000]
      31. 7.5.31 PAP path AB Gain Attenuation Step Register (address = 0x29) [reset = 0x0000]
      32. 7.5.32 PAP path AB Wait Time Register (address = 0x2A) [reset = 0x0000]
      33. 7.5.33 PAP path CD Gain Attenuation Step Register (address = 0x2B) [reset = 0x0000]
      34. 7.5.34 PAP Path CD Wait Time Register (address = 0x2C) [reset = 0x0000]
      35. 7.5.35 PAP path AB Configuration Register (address = 0x2D) [reset = 0x0FFF]
      36. 7.5.36 PAP path CD Configuration Register (address = 0x2E) [reset = 0x0FFF]
      37. 7.5.37 DAC SPI Configuration Register (address = 0x2F) [reset = 0x0000]
      38. 7.5.38 DAC SPI Constant Register (address = 0x30) [reset = 0x0000]
      39. 7.5.39 Gain for path AB Register (address = 0x32) [reset = 0x0400]
      40. 7.5.40 Gain for path CD Register (address = 0x33) [reset = 0x0400]
      41. 7.5.41 JESD Error Counter Register (address = 0x41) [reset = 0x0000]
      42. 7.5.42 JESD ID 1 Register (address = 0x46) [reset = 0x0044]
      43. 7.5.43 JESD ID 2 Register (address = 0x47) [reset = 0x190A]
      44. 7.5.44 JESD ID 3 and Subclass Register (address = 0x48) [reset = 0x31C3]
      45. 7.5.45 JESD Lane Enable Register (address = 0x4A) [reset = 0x0003]
      46. 7.5.46 JESD RBD Buffer and Frame Octets Register (address = 0x4B) [reset = 0x1300]
      47. 7.5.47 JESD K and L Parameters Register (address = 0x4C) [reset = 0x1303]
      48. 7.5.48 JESD M and S Parameters Register (address = 0x4D) [reset = 0x0100]
      49. 7.5.49 JESD N, HD and SCR Parameters Register (address = 0x4E) [reset = 0x0F4F]
      50. 7.5.50 JESD Character Match and Other Register (address = 0x4F) [reset = 0x1CC1]
      51. 7.5.51 JESD Link Configuration Data Register (address = 0x50) [reset = 0x0000]
      52. 7.5.52 JESD Sync Request Register (address = 0x51) [reset = 0x00FF]
      53. 7.5.53 JESD Error Output Register (address = 0x52) [reset = 0x00FF]
      54. 7.5.54 JESD ILA Check 1 Register (address = 0x53) [reset = 0x0100]
      55. 7.5.55 JESD ILA Check 2 Register (address = 0x54) [reset = 0x8E60]
      56. 7.5.56 JESD SYSREF Mode Register (address = 0x5C) [reset = 0x0001]
      57. 7.5.57 JESD Crossbar Configuration 1 Register (address = 0x5F) [reset = 0x0123]
      58. 7.5.58 JESD Crossbar Configuration 2 Register (address = 0x60) [reset = 0x4567]
      59. 7.5.59 JESD Alarms for Lane 0 Register (address = 0x64) [reset = 0x0000]
      60. 7.5.60 JESD Alarms for Lane 1 Register (address = 0x65) [reset = 0x0000]
      61. 7.5.61 JESD Alarms for Lane 2 Register (address = 0x66) [reset = 0x0000]
      62. 7.5.62 JESD Alarms for Lane 3 Register (address = 0x67) [reset = 0x0000]
      63. 7.5.63 JESD Alarms for Lane 4 Register (address = 0x68) [reset = 0x0000]
      64. 7.5.64 JESD Alarms for Lane 5 Register (address = 0x69) [reset = 0x0000]
      65. 7.5.65 JESD Alarms for Lane 6 Register (address = 0x6A [reset = 0x0000]
      66. 7.5.66 JESD Alarms for Lane 7 Register (address = 0x6B) [reset = 0x0000]
      67. 7.5.67 SYSREF and PAP Alarms Register (address = 0x6C) [reset = 0x0000]
      68. 7.5.68 Clock Divider Alarms 1 Register (address = 0x6D) [reset = 0x0000]
      69. 7.5.69 Clock Configuration Register (address = 0x0A) [reset = 0xFC03]
      70. 7.5.70 Sleep Configuration Register (address = 0x0B) [reset = 0x0022]
      71. 7.5.71 Divided Output Clock Configuration Register (address = 0x0C) [reset = 0x2002]
      72. 7.5.72 DAC Fullscale Current Register (address = 0x0D) [reset = 0xF000]
      73. 7.5.73 Internal SYSREF Generator Register (address = 0x10) [reset = 0x0000]
      74. 7.5.74 Counter for Internal SYSREF Generator Register (address = 0x11) [reset = 0x0000]
      75. 7.5.75 SPI SYSREF for Internal SYSREF Generator Register (address = 0x12) [reset = 0x0000]
      76. 7.5.76 Digital Test Signals Register (address = 0x1B) [reset = 0x0000]
      77. 7.5.77 Sleep Pin Control Register (address = 0x23) [reset = 0xFFFF]
      78. 7.5.78 SYSREF Capture Circuit Control Register (address = 0x24) [reset = 0x1000]
      79. 7.5.79 Clock Input and PLL Configuration Register (address = 0x31) [reset = 0x0200]
      80. 7.5.80 PLL Configuration 1 Register (address = 0x32) [reset = 0x0308]
      81. 7.5.81 PLL Configuration 2 Register (address = 0x33) [reset = 0x4018]
      82. 7.5.82 LVDS Output Configuration Register (address = 0x34) [reset = 0x0000]
      83. 7.5.83 Fuse Farm clock divider Register (address = 0x35) [reset = 0x0018]
      84. 7.5.84 Serdes Clock Configuration Register (address = 0x3B) [reset = 0x1802]
      85. 7.5.85 Serdes PLL Configuration Register (address = 0x3C) [reset = 0x8228]
      86. 7.5.86 Serdes Configuration 1 Register (address = 0x3D) [reset = 0x0x0088]
      87. 7.5.87 Serdes Configuration 2 Register (address = 0x3E) [reset = 0x0x0909]
      88. 7.5.88 Serdes Polarity Control Register (address = 0x3F) [reset = 0x0000]
      89. 7.5.89 JESD204B SYNCB OUTPUT Register (address = 0x76) [reset = 0x0000]
  9. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Start-up Sequence
    2. 8.2 Typical Application: Multi-band Radio Frequency Transmitter
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Calculating the JESD204B SerDes Rate
        2. 8.2.2.2 Calculating valid JESD204B SYSREF Frequency
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power Supply Sequencing
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. Device and Documentation Support
    1. 9.1 接收文档更新通知
    2. 9.2 支持资源
    3. 9.3 Trademarks
    4. 9.4 静电放电警告
    5. 9.5 术语表
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

SerDes PLL

The DAC38RFxx has two integrated PLLs, one PLL is to provide the clocking of DAC; the other PLL is to provide the clocking for the high speed SerDes. The reference frequency of the SerDes PLL can be in the range of 100-800 MHz nominal, and 300-800 MHz optimal. The reference frequency is derived from DACCLK divided down by the value in field SerDes_REFCLK_DIV in register SRDS_CLK_CFG (8.5.84), as shown in Figure 7-8. Field SerDes_CLK_SEL in register SRDS_CLK_CFG (8.5.84) determines if the DACCLK input or DAC PLL output is used as the source of the SerDes PLL reference. If the DACCLK input is used, a pre-divider set by field SerDes_REFCLK_PREDIV in register SRDS_CLK_CFG (8.5.84) should be used to reduce the frequency of the DACCLK.

GUID-66B32CCC-66E2-420C-A7EF-1AAB960089C9-low.gifFigure 7-8 Reference Clock of SerDes PLL

During normal operation, the clock generated by PLL is 4-25 times the reference frequency, according to the multiply factor selected through the field MPY] in register SRDS_PLL_CFG (8.5.85). To select the appropriate multiply factor and reference clock frequency, it is first necessary to determine the required PLL output clock frequency. The relationship between the PLL output clock frequency and the lane rate is determined by field RATE in register SRDS_CFG2 (8.5.87) is shown in PLL. Having computed the PLL output frequency, the reference frequency can be obtained by dividing this by the multiply factor specified through MPY.

Table 7-3 PLL
RATELINE RATEPLL OUTPUT FREQUENCY
00x Gbps0.25x GHz
01x Gbps0.5x GHz
10x Gbps1x GHz
11x Gbps2x GHz
Table 7-4 SerDes PLL Multiplier (MPY) Values
MPYEFFECT
0x104x
0x145x
0x186x
0x208x
0x218.25x
0x2810x
0x3012x
0x3212.5x
0x3C15x
0x4016x
0x4216.5x
0x5020x
0x5822x
0x6425x
Other codesReserved

The wide range of multiply factors combined with the different rate modes means it is often possible to achieve a given line rate from multiple different reference frequencies. The configuration which utilizes the highest reference frequency achievable is always preferable.

The SerDes PLL VCO must be in the nominal range of 1.5625 - 3.125 GHz. It is necessary to adjust the loop filter depending on the operating frequency of the VCO. If the PLL output frequency is below 2.17 GHz, VRANGE in register SRDS_PLL_CFG (8.5.84) should be set high.

Performance of the integrated PLL can be optimized according to the jitter characteristics of the reference clock by setting the appropriate loop bandwidth through field LB in register SRDS_PLL_CFG (8.5.84). The loop bandwidth is obtained by dividing the reference frequency by BWSCALE, where the BWSCALE is a function of both LB and PLL output frequency as shown in Table 7-5.

Table 7-5 SerDes PLL Loop Bandwidth Selection
LBEFFECTBWSCALE vs PLL OUTPUT FREQUENCY
3.125 GHz2.17 GHz1.5625 GHz
00Medium loop bandwidth131416
01Ultra high loop bandwidth788
10Low loop bandwidth212330
11High loop bandwidth101114

An approximate loop bandwidth of 8 – 30 MHz is suitable and recommended for most systems where the reference clock is through low jitter clock input buffer. For systems where the reference clock is through a low jitter input cell, but of low quality, an approximate loop bandwidth of less than 8 MHz may offer better performance. For systems where the reference clock is cleaned through an ultra-low jitter LC-based cleaner PLL, a high loop bandwidth up to 60 MHz is more appropriate. Note that the use of ultra-high loop bandwidth setting is not recommended for PLL multiply factor of less than 8.

A free running clock output is available when field ENDIVCLK in register SRDS_PLL_CFG (8.5.85) is set high. It runs at a fixed divided-by-80 of the PLL output frequency and can be output on the ALARM pin by setting field DTEST to “0001” (lanes 0 – 3) or “0010” (lanes 4 – 7) in register DTEST (8.5.76).