JAJSEY1 April   2019 ADC12DJ5200RF

ADVANCE INFORMATION for pre-production products; subject to change without notice.  

  1. 特長
  2. アプリケーション
  3. 概要
    1.     ADC12DJ5200RF ブロック図
  4. 改訂履歴
  5. 概要 (続き)
  6. Pin Configuration and Functions
    1.     Pin Functions
  7. Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics: DC Specifications
    6. 7.6  Electrical Characteristics: Power Consumption
    7. 7.7  Electrical Characteristics: AC Specifications (Dual-Channel Mode)
    8. 7.8  Electrical Characteristics: AC Specifications (Single-Channel Mode)
    9. 7.9  Timing Requirements
    10. 7.10 Switching Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Device Comparison
      2. 8.3.2 Analog Inputs
        1. 8.3.2.1 Analog Input Protection
        2. 8.3.2.2 Full-Scale Voltage (VFS) Adjustment
        3. 8.3.2.3 Analog Input Offset Adjust
      3. 8.3.3 ADC Core
        1. 8.3.3.1 ADC Theory of Operation
        2. 8.3.3.2 ADC Core Calibration
        3. 8.3.3.3 Analog Reference Voltage
        4. 8.3.3.4 ADC Overrange Detection
        5. 8.3.3.5 Code Error Rate (CER)
      4. 8.3.4 Temperature Monitoring Diode
      5. 8.3.5 Timestamp
      6. 8.3.6 Clocking
        1. 8.3.6.1 Noiseless Aperture Delay Adjustment (tAD Adjust)
        2. 8.3.6.2 Aperture Delay Ramp Control (TAD_RAMP)
        3. 8.3.6.3 SYSREF Capture for Multi-Device Synchronization and Deterministic Latency
          1. 8.3.6.3.1 SYSREF Position Detector and Sampling Position Selection (SYSREF Windowing)
          2. 8.3.6.3.2 Automatic SYSREF Calibration
      7. 8.3.7 Digital Down Converters (DDC)
        1. 8.3.7.1 Numerically-Controlled Oscillator and Complex Mixer
          1. 8.3.7.1.1 NCO Fast Frequency Hopping (FFH)
          2. 8.3.7.1.2 NCO Selection
          3. 8.3.7.1.3 Basic NCO Frequency Setting Mode
          4. 8.3.7.1.4 Rational NCO Frequency Setting Mode
          5. 8.3.7.1.5 NCO Phase Offset Setting
          6. 8.3.7.1.6 NCO Phase Synchronization
        2. 8.3.7.2 Decimation Filters
        3. 8.3.7.3 Output Data Format
        4. 8.3.7.4 Decimation Settings
          1. 8.3.7.4.1 Decimation Factor
          2. 8.3.7.4.2 DDC Gain Boost
      8. 8.3.8 JESD204C Interface
        1. 8.3.8.1 Transport Layer
        2. 8.3.8.2 Scrambler
        3. 8.3.8.3 Link Layer
        4. 8.3.8.4 8B/10B Link Layer
          1. 8.3.8.4.1 Data Encoding (8B/10B)
          2. 8.3.8.4.2 Multiframes and the Local Multiframe Clock (LMFC)
          3. 8.3.8.4.3 Code Group Synchronization (CGS)
          4. 8.3.8.4.4 Initial Lane Alignment Sequence (ILAS)
          5. 8.3.8.4.5 Frame and Multiframe Monitoring
        5. 8.3.8.5 64B/66B Link Layer
          1. 8.3.8.5.1 64B/66B Encoding
          2. 8.3.8.5.2 Multiblocks, Extended Multiblocks and the Local Extended Multiblock Clock (LEMC)
          3. 8.3.8.5.3 Block, Multiblock and Extended Multiblock Alignment using Sync Header
            1. 8.3.8.5.3.1 Cyclic Redundancy Check (CRC) Mode
            2. 8.3.8.5.3.2 Forward Error Correction (FEC) Mode
          4. 8.3.8.5.4 Initial Lane Alignment
          5. 8.3.8.5.5 Block, Multiblock and Extended Multiblock Alignment Monitoring
        6. 8.3.8.6 Physical Layer
          1. 8.3.8.6.1 SerDes Pre-Emphasis
        7. 8.3.8.7 JESD204C Enable
        8. 8.3.8.8 Multi-Device Synchronization and Deterministic Latency
        9. 8.3.8.9 Operation in Subclass 0 Systems
      9. 8.3.9 Alarm Monitoring
        1. 8.3.9.1 NCO Upset Detection
        2. 8.3.9.2 Clock Upset Detection
        3. 8.3.9.3 FIFO Upset Detection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Dual-Channel Mode
      2. 8.4.2 Single-Channel Mode (DES Mode)
      3. 8.4.3 JESD204C Modes
        1. 8.4.3.1 JESD204C Transport Layer Data Formats
        2. 8.4.3.2 64B/66B Sync Header Stream Configuration
        3. 8.4.3.3 Dual DDC and Redundant Data Mode
      4. 8.4.4 Power-Down Modes
      5. 8.4.5 Test Modes
        1. 8.4.5.1 Serializer Test-Mode Details
        2. 8.4.5.2 PRBS Test Modes
        3. 8.4.5.3 Clock Pattern Mode
        4. 8.4.5.4 Ramp Test Mode
        5. 8.4.5.5 Short and Long Transport Test Mode
          1. 8.4.5.5.1 Short Transport Test Pattern
          2. 8.4.5.5.2 Long Transport Test Pattern
        6. 8.4.5.6 D21.5 Test Mode
        7. 8.4.5.7 K28.5 Test Mode
        8. 8.4.5.8 Repeated ILA Test Mode
        9. 8.4.5.9 Modified RPAT Test Mode
      6. 8.4.6 Calibration Modes and Trimming
        1. 8.4.6.1 Foreground Calibration Mode
        2. 8.4.6.2 Background Calibration Mode
        3. 8.4.6.3 Low-Power Background Calibration (LPBG) Mode
      7. 8.4.7 Offset Calibration
      8. 8.4.8 Trimming
    5. 8.5 Programming
      1. 8.5.1 Using the Serial Interface
        1. 8.5.1.1 SCS
        2. 8.5.1.2 SCLK
        3. 8.5.1.3 SDI
        4. 8.5.1.4 SDO
        5. 8.5.1.5 Streaming Mode
    6. 8.6 SPI_Register_Map Registers
      1. 8.6.1   CONFIG_A Register (Address = 0x0) [reset = 0x30]
        1. Table 60. CONFIG_A Register Field Descriptions
      2. 8.6.2   DEVICE_CONFIG Register (Address = 0x2) [reset = 0x00]
        1. Table 61. DEVICE_CONFIG Register Field Descriptions
      3. 8.6.3   CHIP_TYPE Register (Address = 0x3) [reset = 0x03]
        1. Table 62. CHIP_TYPE Register Field Descriptions
      4. 8.6.4   CHIP_ID Register (Address = 0x4) [reset = 0x0]
        1. Table 63. CHIP_ID Register Field Descriptions
      5. 8.6.5   VENDOR_ID Register (Address = 0xC) [reset = 0x0]
        1. Table 64. VENDOR_ID Register Field Descriptions
      6. 8.6.6   USR0 Register (Address = 0x10) [reset = 0x00]
        1. Table 65. USR0 Register Field Descriptions
      7. 8.6.7   CLK_CTRL0 Register (Address = 0x29) [reset = 0x00]
        1. Table 66. CLK_CTRL0 Register Field Descriptions
      8. 8.6.8   CLK_CTRL1 Register (Address = 0x2A) [reset = 0x00]
        1. Table 67. CLK_CTRL1 Register Field Descriptions
      9. 8.6.9   SYSREF_POS Register (Address = 0x2C) [reset = 0x0]
        1. Table 68. SYSREF_POS Register Field Descriptions
      10. 8.6.10  FS_RANGE_A Register (Address = 0x30) [reset = 0x0]
        1. Table 69. FS_RANGE_A Register Field Descriptions
      11. 8.6.11  FS_RANGE_B Register (Address = 0x32) [reset = 0x0]
        1. Table 70. FS_RANGE_B Register Field Descriptions
      12. 8.6.12  BG_BYPASS Register (Address = 0x38) [reset = 0x00]
        1. Table 71. BG_BYPASS Register Field Descriptions
      13. 8.6.13  TMSTP_CTRL Register (Address = 0x3B) [reset = 0x00]
        1. Table 72. TMSTP_CTRL Register Field Descriptions
      14. 8.6.14  SER_PE Register (Address = 0x48) [reset = 0x00]
        1. Table 73. SER_PE Register Field Descriptions
      15. 8.6.15  INPUT_MUX Register (Address = 0x60) [reset = 0x01]
        1. Table 74. INPUT_MUX Register Field Descriptions
      16. 8.6.16  CAL_EN Register (Address = 0x61) [reset = 0x01]
        1. Table 75. CAL_EN Register Field Descriptions
      17. 8.6.17  CAL_CFG0 Register (Address = 0x62) [reset = 0x01]
        1. Table 76. CAL_CFG0 Register Field Descriptions
      18. 8.6.18  CAL_AVG Register (Address = 0x68) [reset = 0x61]
        1. Table 77. CAL_AVG Register Field Descriptions
      19. 8.6.19  CAL_STATUS Register (Address = 0x6A) [reset = 0x0]
        1. Table 78. CAL_STATUS Register Field Descriptions
      20. 8.6.20  CAL_PIN_CFG Register (Address = 0x6B) [reset = 0x00]
        1. Table 79. CAL_PIN_CFG Register Field Descriptions
      21. 8.6.21  CAL_SOFT_TRIG Register (Address = 0x6C) [reset = 0x01]
        1. Table 80. CAL_SOFT_TRIG Register Field Descriptions
      22. 8.6.22  CAL_LP Register (Address = 0x6E) [reset = 0x88]
        1. Table 81. CAL_LP Register Field Descriptions
      23. 8.6.23  CAL_DATA_EN Register (Address = 0x70) [reset = 0x00]
        1. Table 82. CAL_DATA_EN Register Field Descriptions
      24. 8.6.24  CAL_DATA Register (Address = 0x71) [reset = 0x0]
        1. Table 83. CAL_DATA Register Field Descriptions
      25. 8.6.25  GAIN_TRIM_A Register (Address = 0x7A) [reset = 0x0]
        1. Table 84. GAIN_TRIM_A Register Field Descriptions
      26. 8.6.26  GAIN_TRIM_B Register (Address = 0x7B) [reset = 0x0]
        1. Table 85. GAIN_TRIM_B Register Field Descriptions
      27. 8.6.27  BG_TRIM Register (Address = 0x7C) [reset = 0x0]
        1. Table 86. BG_TRIM Register Field Descriptions
      28. 8.6.28  RTRIM_A Register (Address = 0x7E) [reset = 0x0]
        1. Table 87. RTRIM_A Register Field Descriptions
      29. 8.6.29  RTRIM_B Register (Address = 0x7F) [reset = 0x0]
        1. Table 88. RTRIM_B Register Field Descriptions
      30. 8.6.30  ADC_DITH Register (Address = 0x9D) [reset = 0x0]
        1. Table 89. ADC_DITH Register Field Descriptions
      31. 8.6.31  B0_TIME_0 Register (Address = 0x102) [reset = 0x0]
        1. Table 90. B0_TIME_0 Register Field Descriptions
      32. 8.6.32  B0_TIME_90 Register (Address = 0x103) [reset = 0x0]
        1. Table 91. B0_TIME_90 Register Field Descriptions
      33. 8.6.33  B1_TIME_0 Register (Address = 0x112) [reset = 0x0]
        1. Table 92. B1_TIME_0 Register Field Descriptions
      34. 8.6.34  B1_TIME_90 Register (Address = 0x113) [reset = 0x0]
        1. Table 93. B1_TIME_90 Register Field Descriptions
      35. 8.6.35  B4_TIME_0 Register (Address = 0x142) [reset = 0x0]
        1. Table 94. B4_TIME_0 Register Field Descriptions
      36. 8.6.36  B5_TIME_0 Register (Address = 0x152) [reset = 0x0]
        1. Table 95. B5_TIME_0 Register Field Descriptions
      37. 8.6.37  LSB_CTRL Register (Address = 0x160) [reset = 0x00]
        1. Table 96. LSB_CTRL Register Field Descriptions
      38. 8.6.38  JESD_EN Register (Address = 0x200) [reset = 0x01]
        1. Table 97. JESD_EN Register Field Descriptions
      39. 8.6.39  JMODE Register (Address = 0x201) [reset = 0x02]
        1. Table 98. JMODE Register Field Descriptions
      40. 8.6.40  KM1 Register (Address = 0x202) [reset = 0x1]
        1. Table 99. KM1 Register Field Descriptions
      41. 8.6.41  JSYNC_N Register (Address = 0x203) [reset = 0x01]
        1. Table 100. JSYNC_N Register Field Descriptions
      42. 8.6.42  JCTRL Register (Address = 0x204) [reset = 0x02]
        1. Table 101. JCTRL Register Field Descriptions
      43. 8.6.43  JTEST Register (Address = 0x205) [reset = 0x00]
        1. Table 102. JTEST Register Field Descriptions
      44. 8.6.44  DID Register (Address = 0x206) [reset = 0x00]
        1. Table 103. DID Register Field Descriptions
      45. 8.6.45  FCHAR Register (Address = 0x207) [reset = 0x00]
        1. Table 104. FCHAR Register Field Descriptions
      46. 8.6.46  JESD_STATUS Register (Address = 0x208) [reset = 0x0]
        1. Table 105. JESD_STATUS Register Field Descriptions
      47. 8.6.47  PD_CH Register (Address = 0x209) [reset = 0x00]
        1. Table 106. PD_CH Register Field Descriptions
      48. 8.6.48  JEXTRA_A Register (Address = 0x20A) [reset = 0x00]
        1. Table 107. JEXTRA_A Register Field Descriptions
      49. 8.6.49  JEXTRA_B Register (Address = 0x20B) [reset = 0x00]
        1. Table 108. JEXTRA_B Register Field Descriptions
      50. 8.6.50  SHMODE Register (Address = 0x20F) [reset = 0x00]
        1. Table 109. SHMODE Register Field Descriptions
      51. 8.6.51  DDC_CFG Register (Address = 0x210) [reset = 0x00]
        1. Table 110. DDC_CFG Register Field Descriptions
      52. 8.6.52  OVR_T0 Register (Address = 0x211) [reset = 0x0]
        1. Table 111. OVR_T0 Register Field Descriptions
      53. 8.6.53  OVR_T1 Register (Address = 0x212) [reset = 0x0]
        1. Table 112. OVR_T1 Register Field Descriptions
      54. 8.6.54  OVR_CFG Register (Address = 0x213) [reset = 0x07]
        1. Table 113. OVR_CFG Register Field Descriptions
      55. 8.6.55  CMODE Register (Address = 0x214) [reset = 0x00]
        1. Table 114. CMODE Register Field Descriptions
      56. 8.6.56  CSEL Register (Address = 0x215) [reset = 0x00]
        1. Table 115. CSEL Register Field Descriptions
      57. 8.6.57  DIG_BIND Register (Address = 0x216) [reset = 0x02]
        1. Table 116. DIG_BIND Register Field Descriptions
      58. 8.6.58  NCO_RDIV Register (Address = 0x217) [reset = 0x0000]
        1. Table 117. NCO_RDIV Register Field Descriptions
      59. 8.6.59  NCO_SYNC Register (Address = 0x219) [reset = 0x02]
        1. Table 118. NCO_SYNC Register Field Descriptions
      60. 8.6.60  FREQA0 Register (Address = 0x220) [reset = 0x0]
        1. Table 119. FREQA0 Register Field Descriptions
      61. 8.6.61  PHASEA0 Register (Address = 0x224) [reset = 0x0000]
        1. Table 120. PHASEA0 Register Field Descriptions
      62. 8.6.62  FREQA1 Register (Address = 0x228) [reset = 0x0]
        1. Table 121. FREQA1 Register Field Descriptions
      63. 8.6.63  PHASEA1 Register (Address = 0x22C) [reset = 0x0000]
        1. Table 122. PHASEA1 Register Field Descriptions
      64. 8.6.64  FREQA2 Register (Address = 0x230) [reset = 0x0]
        1. Table 123. FREQA2 Register Field Descriptions
      65. 8.6.65  PHASEA2 Register (Address = 0x234) [reset = 0x0000]
        1. Table 124. PHASEA2 Register Field Descriptions
      66. 8.6.66  FREQA3 Register (Address = 0x238) [reset = 0x0]
        1. Table 125. FREQA3 Register Field Descriptions
      67. 8.6.67  PHASEA3 Register (Address = 0x23C) [reset = 0x0000]
        1. Table 126. PHASEA3 Register Field Descriptions
      68. 8.6.68  FREQB0 Register (Address = 0x240) [reset = 0x0]
        1. Table 127. FREQB0 Register Field Descriptions
      69. 8.6.69  PHASEB0 Register (Address = 0x244) [reset = 0x0000]
        1. Table 128. PHASEB0 Register Field Descriptions
      70. 8.6.70  FREQB1 Register (Address = 0x248) [reset = 0x0]
        1. Table 129. FREQB1 Register Field Descriptions
      71. 8.6.71  PHASEB1 Register (Address = 0x24C) [reset = 0x0000]
        1. Table 130. PHASEB1 Register Field Descriptions
      72. 8.6.72  FREQB2 Register (Address = 0x250) [reset = 0x0]
        1. Table 131. FREQB2 Register Field Descriptions
      73. 8.6.73  PHASEB2 Register (Address = 0x254) [reset = 0x0000]
        1. Table 132. PHASEB2 Register Field Descriptions
      74. 8.6.74  FREQB3 Register (Address = 0x258) [reset = 0x0]
        1. Table 133. FREQB3 Register Field Descriptions
      75. 8.6.75  PHASEB3 Register (Address = 0x25C) [reset = 0x0000]
        1. Table 134. PHASEB3 Register Field Descriptions
      76. 8.6.76  SPIN_ID Register (Address = 0x297) [reset = 0x0]
        1. Table 135. SPIN_ID Register Field Descriptions
      77. 8.6.77  SRC_EN Register (Address = 0x2B0) [reset = 0x00]
        1. Table 136. SRC_EN Register Field Descriptions
      78. 8.6.78  SRC_CFG Register (Address = 0x2B1) [reset = 0x05]
        1. Table 137. SRC_CFG Register Field Descriptions
      79. 8.6.79  SRC_STATUS Register (Address = 0x2B2) [reset = 0x0]
        1. Table 138. SRC_STATUS Register Field Descriptions
      80. 8.6.80  TAD Register (Address = 0x2B5) [reset = 0x00]
        1. Table 139. TAD Register Field Descriptions
      81. 8.6.81  TAD_RAMP Register (Address = 0x2B8) [reset = 0x00]
        1. Table 140. TAD_RAMP Register Field Descriptions
      82. 8.6.82  ALARM Register (Address = 0x2C0) [reset = 0x0]
        1. Table 141. ALARM Register Field Descriptions
      83. 8.6.83  ALM_STATUS Register (Address = 0x2C1) [reset = 0x3]
        1. Table 142. ALM_STATUS Register Field Descriptions
      84. 8.6.84  ALM_MASK Register (Address = 0x2C2) [reset = 0x3]
        1. Table 143. ALM_MASK Register Field Descriptions
      85. 8.6.85  FIFO_LANE_ALM Register (Address = 0x2C4) [reset = 0x0]
        1. Table 144. FIFO_LANE_ALM Register Field Descriptions
      86. 8.6.86  TADJ_A Register (Address = 0x310) [reset = 0x0]
        1. Table 145. TADJ_A Register Field Descriptions
      87. 8.6.87  TADJ_B Register (Address = 0x313) [reset = 0x0]
        1. Table 146. TADJ_B Register Field Descriptions
      88. 8.6.88  TADJ_A_FG90_VINA Register (Address = 0x314) [reset = 0x0]
        1. Table 147. TADJ_A_FG90_VINA Register Field Descriptions
      89. 8.6.89  TADJ_B_FG0_VINA Register (Address = 0x315) [reset = 0x0]
        1. Table 148. TADJ_B_FG0_VINA Register Field Descriptions
      90. 8.6.90  TADJ_A_FG90_VINB Register (Address = 0x31A) [reset = 0x0]
        1. Table 149. TADJ_A_FG90_VINB Register Field Descriptions
      91. 8.6.91  TADJ_B_FG0_VINB Register (Address = 0x31B) [reset = 0x0]
        1. Table 150. TADJ_B_FG0_VINB Register Field Descriptions
      92. 8.6.92  OADJ_A_FG0_VINA Register (Address = 0x344) [reset = 0x0]
        1. Table 151. OADJ_A_FG0_VINA Register Field Descriptions
      93. 8.6.93  OADJ_A_FG0_VINB Register (Address = 0x346) [reset = 0x0]
        1. Table 152. OADJ_A_FG0_VINB Register Field Descriptions
      94. 8.6.94  OADJ_A_FG90_VINA Register (Address = 0x348) [reset = 0x0]
        1. Table 153. OADJ_A_FG90_VINA Register Field Descriptions
      95. 8.6.95  OADJ_A_FG90_VINB Register (Address = 0x34A) [reset = 0x0]
        1. Table 154. OADJ_A_FG90_VINB Register Field Descriptions
      96. 8.6.96  OADJ_B_FG0_VINA Register (Address = 0x34C) [reset = 0x0]
        1. Table 155. OADJ_B_FG0_VINA Register Field Descriptions
      97. 8.6.97  OADJ_B_FG0_VINB Register (Address = 0x34E) [reset = 0x0]
        1. Table 156. OADJ_B_FG0_VINB Register Field Descriptions
      98. 8.6.98  GAIN_B0 Register (Address = 0x360) [reset = 0x0]
        1. Table 157. GAIN_B0 Register Field Descriptions
      99. 8.6.99  GAIN_B1 Register (Address = 0x361) [reset = 0x0]
        1. Table 158. GAIN_B1 Register Field Descriptions
      100. 8.6.100 GAIN_B4 Register (Address = 0x364) [reset = 0x0]
        1. Table 159. GAIN_B4 Register Field Descriptions
      101. 8.6.101 GAIN_B5 Register (Address = 0x365) [reset = 0x0]
        1. Table 160. GAIN_B5 Register Field Descriptions
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Wideband RF Sampling Receiver
        1. 9.2.1.1 Design Requirements
          1. 9.2.1.1.1 Input Signal Path
          2. 9.2.1.1.2 Clocking
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Calculating Values of AC-Coupling Capacitors
      2. 9.2.2 Reconfigurable Dual-Channel 5-GSPS or Single-Channel 10-Gsps Oscilloscope
        1. 9.2.2.1 Design Requirements
          1. 9.2.2.1.1 Input Signal Path
          2. 9.2.2.1.2 Clocking
          3. 9.2.2.1.3 ADC12DJ5200RF
    3. 9.3 Initialization Set Up
  10. 10Power Supply Recommendations
    1. 10.1 Power Sequencing
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 デベロッパー・ネットワークの製品に関する免責事項
      2. 12.1.2 開発サポート
    2. 12.2 ドキュメントのサポート
      1. 12.2.1 関連資料
    3. 12.3 ドキュメントの更新通知を受け取る方法
    4. 12.4 コミュニティ・リソース
    5. 12.5 商標
    6. 12.6 静電気放電に関する注意事項
    7. 12.7 Glossary
  13. 13メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

Layout Guidelines

There are many critical signals that require specific care during board design:

  1. Analog input signals
  2. CLK and SYSREF
  3. JESD204C data outputs
  4. Power connections
  5. Ground connections

The analog input signals, clock signals and JESD204C data outputs must be routed for excellent signal quality at high frequencies, but should also be routed for maximum isolation from each other. Use the following general practices:

  1. Route using loosely coupled 100-Ω differential traces when possible. This routing minimizes impact of corners and length-matching serpentines on pair impedance.
  2. Provide adequate pair-to-pair spacing to minimize crosstalk, especially with loosely coupled differential traces. Tightly coupled differential traces may be used to reduce self-radiated noise or to improve neighboring trace noise immunity when adequate spacing cannot be provided.
  3. Provide adequate ground plane pour spacing to minimize coupling with the high-speed traces. Any ground plane pour must have sufficient via connections to the main ground plane of the board. Do not use floating or poorly connected ground pours.
  4. Use smoothly radiused corners. Avoid 45- or 90-degree bends to reduce impedance mismatches.
  5. Incorporate ground plane cutouts at component landing pads to avoid impedance discontinuities at these locations. Cut-out below the landing pads on one or multiple ground planes to achieve a pad size or stackup height that achieves the needed 50-Ω, single-ended impedance.
  6. Avoid routing traces near irregularities in the reference ground planes. Irregularities include cuts in the ground plane or ground plane clearances associated with power and signal vias and through-hole component leads.
  7. Provide symmetrically located ground tie vias adjacent to any high-speed signal vias at an appropriate spacing as determined by the maximum frequency the trace will transport (<< λMIN/8).
  8. When high-speed signals must transition to another layer using vias, transition as far through the board as possible (top to bottom is best case) to minimize via stubs on top or bottom of the vias. If layer selection is not flexible, use back-drilled or buried, blind vias to eliminate stubs. Always place ground vias close to the signal vias when transitioning between layers to provide a nearby ground return path.

Pay particular attention to potential coupling between JESD204C data output routing and the analog input routing. Switching noise from the JESD204C outputs can couple into the analog input traces and show up as wideband noise due to the high input bandwidth fo the ADC. Ideally, route the JESD204C data outputs on a separate layer from the ADC input traces to avoid noise coupling (not shown in the Layout Example section). Tightly coupled traces can also be used to reduce noise coupling.

Impedance mismatch between the CLK± input pins and the clock source can result in reduced amplitude of the clock signal at the ADC CLK± pins due to signal reflections or standing waves. A reduction in the clock amplitude may degrade ADC noise performance, especially at high input frequencies. To avoid this, keep the clock source close to the ADC (as shown in the Layout Example section) or implement impedance matching at the ADC CLK± input pins.

In addition, TI recommends performing signal quality simulations of the critical signal traces before committing to fabrication. Insertion loss, return loss, and time domain reflectometry (TDR) evaluations should be done.

The power and ground connections for the device are also very important. These rules must be followed:

  1. Provide low-resistance connection paths to all power and ground pins.
  2. Use multiple power layers if necessary to access all pins.
  3. Avoid narrow isolated paths that increase connection resistance.
  4. Use a signal, ground, or power circuit board stackup to maximum coupling between the ground and power planes.