JAJSEY1 April   2019 ADC12DJ5200RF

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

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     ADC12DJ5200RF ブロック図
  4. 4 改訂履歴
  5. 5 概要 (続き)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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. 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. 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

10 Power Supply Recommendations

The device requires two different power-supply voltages. 1.9-V DC is required for the VA19 power bus and 1.1-V DC is required for the VA11 and VD11 power buses.

The power-supply voltages must be low noise and provide the needed current to achieve rated device performance.

There are two recommended power supply architectures:

  1. Step down using high-efficiency switching converters, followed by a second stage of regulation to provide switching noise reduction and improved voltage accuracy.
  2. Directly step down the final ADC supply voltage using high-efficiency switching converters. This approach provides the best efficiency, but care must be taken to ensure switching noise is minimized to prevent degraded ADC performance.

TI WEBENCH® Power Designer can be used to select and design the individual power supply elements needed: see the WEBENCH® Power Designer

Recommended switching regulators for the first stage include LMS3635-Q1, LMS3655-Q1, TPSM84424 and similar devices.

Recommended low drop-out (LDO), low-noise linear regulators include the TPS7A84, TPS7A83A, TPS7A47 and similar devices.

For the switcher only approach, the ripple filter must be designed to provide sufficient filtering at the switching frequency of the DC-DC converter and harmonics of the switching frequency. Make a note of the switching frequency reported from WEBENCH® and design the EMI filter and capacitor combination to have the notch frequency centered as needed. Each application will have different tolerances for noise on the supply voltage so strict ripple requirements are not provided. Figure 127 and Figure 128 illustrate the two approaches.

ADC12DJ5200RF slvsd97_adc12dj3200_hybrid_power_su.gif

NOTE:

FB = ferrite bead filter.
Figure 127. LDO Linear Regulator Approach Example
ADC12DJ5200RF slvsd97_adcxxdj3200_switching_power.gif

NOTE:

Ripple filter notch frequency to match the fs of the buck converter.

NOTE:

FB = ferrite bead filter.
Figure 128. Switcher-Only Approach Example