ZHCSCX2E January   2014  – October 2017 LM15851

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
    1.     Device Images
      1. 16 倍抽取率 — 频谱响应 ƒS = 4GHz,FIN = 1897MHz(–1dBFS 时),ƒ(NCO_x) = 1827MHz
  4. 修订历史记录
  5. Pin Configuration and Functions
    1.     Pin Functions
  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
    6. 6.6 Timing Requirements
    7. 6.7 Internal Characteristics
    8. 6.8 Switching Characteristics
    9. 6.9 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Signal Acquisition
      2. 7.3.2 The Analog Inputs
        1. 7.3.2.1 Input Clamp
        2. 7.3.2.2 AC Coupled Input Usage
        3. 7.3.2.3 DC Coupled Input Usage
        4. 7.3.2.4 Handling Single-Ended Input Signals
      3. 7.3.3 Clocking
      4. 7.3.4 Over-Range Function
      5. 7.3.5 ADC Core Features
        1. 7.3.5.1 The Reference Voltage
        2. 7.3.5.2 Common-Mode Voltage Generation
        3. 7.3.5.3 Bias Current Generation
        4. 7.3.5.4 Full Scale Range Adjust
        5. 7.3.5.5 Offset Adjust
        6. 7.3.5.6 Power-Down
        7. 7.3.5.7 Built-In Temperature Monitor Diode
      6. 7.3.6 Digital Down Converter (DDC)
        1. 7.3.6.1 NCO/Mixer
        2. 7.3.6.2 NCO Settings
          1. 7.3.6.2.1 NCO Frequency Phase Selection
          2. 7.3.6.2.2 NCO_0, NCO_1, and NCO_2 (NCO_x)
          3. 7.3.6.2.3 NCO_SEL Bits (2:0)
          4. 7.3.6.2.4 NCO Frequency Setting (Eight Total)
            1. 7.3.6.2.4.1 Basic NCO Frequency-Setting Mode
            2. 7.3.6.2.4.2 Rational NCO Frequency Setting Mode
          5. 7.3.6.2.5 NCO Phase-Offset Setting (Eight Total)
          6. 7.3.6.2.6 Programmable DDC Delay
        3. 7.3.6.3 Decimation Filters
        4. 7.3.6.4 DDC Output Data
        5. 7.3.6.5 Decimation Settings
          1. 7.3.6.5.1 Decimation Factor
          2. 7.3.6.5.2 DDC Gain Boost
      7. 7.3.7 Data Outputs
        1. 7.3.7.1 The Digital Outputs
        2. 7.3.7.2 JESD204B Interface Features and Settings
          1. 7.3.7.2.1  Scrambler Enable
          2. 7.3.7.2.2  Frames Per Multi-Frame (K-1)
          3. 7.3.7.2.3  DDR
          4. 7.3.7.2.4  JESD Enable
          5. 7.3.7.2.5  JESD Test Modes
          6. 7.3.7.2.6  Configurable Pre-Emphasis
          7. 7.3.7.2.7  Serial Output-Data Formatting
          8. 7.3.7.2.8  JESD204B Synchronization Features
          9. 7.3.7.2.9  SYSREF
          10. 7.3.7.2.10 SYNC~
          11. 7.3.7.2.11 Code-Group Synchronization
          12. 7.3.7.2.12 Multiple ADC Synchronization
    4. 7.4 Device Functional Modes
      1. 7.4.1 DDC Modes
      2. 7.4.2 Calibration
        1. 7.4.2.1 Foreground Calibration Mode
        2. 7.4.2.2 Background Calibration Mode
      3. 7.4.3 Timing Calibration Mode
      4. 7.4.4 Test-Pattern Modes
        1. 7.4.4.1 Serializer Test-Mode Details
        2. 7.4.4.2 PRBS Test Modes
        3. 7.4.4.3 Ramp Test Mode
        4. 7.4.4.4 Short and Long-Transport Test Mode
        5. 7.4.4.5 D21.5 Test Mode
        6. 7.4.4.6 K28.5 Test Mode
        7. 7.4.4.7 Repeated ILA Test Mode
        8. 7.4.4.8 Modified RPAT Test Mode
    5. 7.5 Programming
      1. 7.5.1 Using the Serial Interface
        1. 7.5.1.1 Streaming Mode
    6. 7.6 Register Map
      1. 7.6.1 Memory Map
      2. 7.6.2 Register Descriptions
        1. 7.6.2.1 Standard SPI-3.0 (0x000 to 0x00F)
          1. Table 34. Standard SPI-3.0 Registers
          2. 7.6.2.1.1  Configuration A Register (address = 0x000) [reset = 0x3C]
            1. Table 35. CFGA Field Descriptions
          3. 7.6.2.1.2  Configuration B Register (address = 0x001) [reset = 0x00]
            1. Table 36. CFGB Field Descriptions
          4. 7.6.2.1.3  Device Configuration Register (address = 0x002) [reset = 0x00]
            1. Table 37. DEVCFG Field Descriptions
          5. 7.6.2.1.4  Chip Type Register (address = 0x003) [reset = 0x03]
            1. Table 38. CHIP_TYPE Field Descriptions
          6. 7.6.2.1.5  Chip Version Register (address = 0x006) [reset = 0x13]
            1. Table 39. CHIP_VERSION Field Descriptions
          7. 7.6.2.1.6  Vendor Identification Register (address = 0x00C to 0x00D) [reset = 0x0451]
            1. Table 40. VENDOR_ID Field Descriptions
        2. 7.6.2.2 User SPI Configuration (0x010 to 0x01F)
          1. 7.6.2.2.1 User SPI Configuration Register (address = 0x010) [reset = 0x00]
            1. Table 42. USR0 Field Descriptions
        3. 7.6.2.3 General Analog, Bias, Band Gap, and Track and Hold (0x020 to 0x02F)
          1. 7.6.2.3.1 Power-On Reset Register (address = 0x021) [reset = 0x00]
            1. Table 44. POR Field Descriptions
          2. 7.6.2.3.2 I/O Gain 0 Register (address = 0x022) [reset = 0x40]
            1. Table 45. IO_GAIN_0 Field Descriptions
          3. 7.6.2.3.3 IO_GAIN_1 Register (address = 0x023) [reset = 0x00]
            1. Table 46. IO_GAIN_1 Field Descriptions
          4. 7.6.2.3.4 I/O Offset 0 Register (address = 0x025) [reset = 0x40]
            1. Table 47. IO_OFFSET_0 Field Descriptions
          5. 7.6.2.3.5 I/O Offset 1 Register (address = 0x026) [reset = 0x00]
            1. Table 48. IO_OFFSET_1 Field Descriptions
        4. 7.6.2.4 Clock (0x030 to 0x03F)
          1. 7.6.2.4.1 Clock Generator Control 0 Register (address = 0x030) [reset = 0xC0]
            1. Table 50. CLKGEN_0 Field Descriptions
          2. 7.6.2.4.2 Clock Generator Status Register (address = 0x031) [reset = 0x07]
            1. Table 51. CLKGEN_1 Field Descriptions
          3. 7.6.2.4.3 Clock Generator Control 2 Register (address = 0x032) [reset = 0x80]
            1. Table 52. CLKGEN_2 Field Descriptions
          4. 7.6.2.4.4 Analog Miscellaneous Register (address = 0x033) [reset = 0xC3]
            1. Table 53. ANA_MISC Field Descriptions
          5. 7.6.2.4.5 Input Clamp Enable Register (address = 0x034) [reset = 0x2F]
            1. Table 54. IN_CL_EN Field Descriptions
        5. 7.6.2.5 Serializer (0x040 to 0x04F)
          1. 7.6.2.5.1 Serializer Configuration Register (address = 0x040) [reset = 0x04]
            1. Table 56. SER_CFG Field Descriptions
        6. 7.6.2.6 ADC Calibration (0x050 to 0x1FF)
          1. 7.6.2.6.1 Calibration Configuration 0 Register (address = 0x050) [reset = 0x06]
            1. Table 58. CAL_CFG0 Field Descriptions
          2. 7.6.2.6.2 Calibration Configuration 1 Register (address = 0x051) [reset = 0xF4]
            1. Table 59. CAL_CFG1 Field Descriptions
          3. 7.6.2.6.3 Calibration Background Control Register (address = 0x057) [reset = 0x10]
            1. Table 60. CAL_BACK Field Descriptions
          4. 7.6.2.6.4 ADC Pattern and Over-Range Enable Register (address = 0x058) [reset = 0x00]
            1. Table 61. ADC_PAT_OVR_EN Field Descriptions
          5. 7.6.2.6.5 Calibration Vectors Register (address = 0x05A) [reset = 0x00]
            1. Table 62. CAL_VECTOR Field Descriptions
          6. 7.6.2.6.6 Calibration Status Register (address = 0x05B) [reset = undefined]
            1. Table 63. CAL_STAT Field Descriptions
          7. 7.6.2.6.7 Timing Calibration Register (address = 0x066) [reset = 0x02]
            1. Table 64. CAL_STAT Field Descriptions
        7. 7.6.2.7 Digital Down Converter and JESD204B (0x200-0x27F)
          1. 7.6.2.7.1  Digital Down-Converter (DDC) Control Register (address = 0x200) [reset = 0x10]
            1. Table 66. DDC_CTRL1 Field Descriptions
          2. 7.6.2.7.2  JESD204B Control 1 Register (address = 0x201) [reset = 0x0F]
            1. Table 67. JESD_CTRL1 Field Descriptions
          3. 7.6.2.7.3  JESD204B Control 2 Register (address = 0x202) [reset = 0x00]
            1. Table 68. JESD_CTRL2 Field Descriptions
          4. 7.6.2.7.4  JESD204B Device ID (DID) Register (address = 0x203) [reset = 0x00]
            1. Table 69. JESD_DID Field Descriptions
          5. 7.6.2.7.5  JESD204B Control 3 Register (address = 0x204) [reset = 0x00]
            1. Table 70. JESD_CTRL3 Field Descriptions
          6. 7.6.2.7.6  JESD204B and System Status Register (address = 0x205) [reset = Undefined]
            1. Table 71. JESD_STATUS Field Descriptions
          7. 7.6.2.7.7  Overrange Threshold 0 Register (address = 0x206) [reset = 0xF2]
            1. Table 72. OVR_T0 Field Descriptions
          8. 7.6.2.7.8  Overrange Threshold 1 Register (address = 0x207) [reset = 0xAB]
            1. Table 73. OVR_T1 Field Descriptions
          9. 7.6.2.7.9  Overrange Period Register (address = 0x208) [reset = 0x00]
            1. Table 74. OVR_N Field Descriptions
          10. 7.6.2.7.10 DDC Configuration Preset Mode Register (address = 0x20C) [reset = 0x00]
            1. Table 75. NCO_MODE Field Descriptions
          11. 7.6.2.7.11 DDC Configuration Preset Select Register (address = 0x20D) [reset = 0x00]
            1. Table 76. NCO_SEL Field Descriptions
          12. 7.6.2.7.12 Rational NCO Reference Divisor Register (address = 0x20E to 0x20F) [reset = 0x0000]
            1. Table 77. NCO_RDIV Field Descriptions
          13. 7.6.2.7.13 NCO Frequency (Preset x) Register (address = see ) [reset = see ]
            1. Table 78. NCO_FREQ_x Field Descriptions
          14. 7.6.2.7.14 NCO Phase (Preset x) Register (address = see ) [reset = see ]
            1. Table 79. NCO_PHASE_x Field Descriptions
          15. 7.6.2.7.15 DDC Delay (Preset x) Register (address = see ) [reset = see ]
            1. Table 80. DDC_DLY_x Field Descriptions
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 RF Sampling Receiver
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
    3. 8.3 Initialization Set-Up
      1. 8.3.1 JESD204B Startup Sequence
    4. 8.4 Dos and Don'ts
      1. 8.4.1 Common Application Pitfalls
  9. Power Supply Recommendations
    1. 9.1 Supply Voltage
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Management
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 开发支持
      3. 11.1.3 器件命名规则
    2. 11.2 文档支持
      1. 11.2.1 相关文档
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 Glossary
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

Multiple ADC Synchronization

The second function for the SYSREF input is to facilitate the precise synchronization of multiple ADCs in a system.

One key challenge is to ensure that this synchronization works is to ensure that the SYSREF inputs are repeatedly captured by the input CLK. Two key elements must occur for the SYSREF inputs to be captured. First, the SYSREF input must be created so that it is synchronous to the input DEVCLK, be an integer sub-harmonic of the multi-frame (K × t(FRAME)) and a repeatable and fixed-phase offset. When this constraint is achieved, repeatedly capturing SYSREF is easier. To further ease this task, the SYSREF signal is routed through a user-adjustable delay which eases the timing requirements with respect to the input DEVCLK signal. The SYSREF delay RDEL is adjusted through bits 3 through 0 in register 0x032.

As long as the SYSREF signal has a fixed timing relationship to DEVCLK, the internal delay can be used to maximize the setup and hold times between the internally delayed SYSREF and the internal DEVCLK signal. These timing relationships are listed in the Timing Requirements table. To find the proper delay setting, the RDEL value is adjusted from minimum to maximum while applying SYSREF and monitoring the SysRefDet and Dirty Capture detect bits. The SysRefDet bit is set whenever a rising edge of SYSREF is detected. The Dirty Capture bit is set whenever the setup or hold time between DEVCLK and the delayed SYSREF is insufficient. The SysRefDetClr bit is used to clear the SysRefDet bit. The Clear Dirty Capture bit is used to clear that bit.

This procedure should be followed to determine the range of delay settings where a clean SYSREF capture is achieved. The delay value at the center of the clean capture range must be loaded as the final RDEL setting. Table 29 lists a summary of the control bits that are used and the monitor bits that are read.

Table 29. SYSREF Capture Control and Status

BIT NAME REGISTER ADDRESSREGISTER BITFUNCTION
RDEL 0x032 3:0 Adjust relative delay between DEVCLK and SYSREF
SysRefDet 0x031 7 Detect if a SYSREF rising edge has been captured (not self clearing)
Dirty Capture 0x031 6 Detect if SYSREF rising edge capture failed setup/hold (not self clearing)
SysRefDetClr 0x030 5 Clear SYSREF detection bit
Clear Dirty Capture 0x030 4 Clear Dirty Capture detection bit
SysRef_Rcvr_En 0x030 7 Enable SYSREF receiver. See the CLKGEN_0 descriptions in the Clock Generator Control 0 Register section for more information.
SysRef_Pr_En 0x030 6 Enable SYSREF processing. See the CLKGEN_0 descriptions in the Clock Generator Control 0 Register section for more information.

One final aspect of multi-device synchronization relates to phase alignment of the NCO phase accumulators when DDC modes are enabled. The NCO phase accumulators are reset during the ILA phase of link startup which means that for multiple ADCs to have NCO phase alignment, all links must be enabled in the same LMFC period. Enabling all links in the same LMFC period requires synchronizing the SYNC~ de-assertion across all data receivers in the system, so that all of the SYNC~ signals are released during the same LMFC period. Using large K values and resulting longer LMFC periods will ease this task, at the expense of potentially higher latency in the receiving device.