SLASE60B September   2015  – January 2019 ADC31JB68

PRODUCTION DATA.  

  1. 1 Features
    1.     Transmitted Eye at Output of 18-Inch, 5-mil. FR4 Microstrip Trace at 5 Gb/s With Optimized De-Emphasis
  2. 2 Applications
  3. 3 Description
    1.     Spectrum With –1-dBFS, 450-MHz Input
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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: Converter Performance
    6. 6.6 Electrical Characteristics: Power Supply
    7. 6.7 Electrical Characteristics: Interface
    8. 6.8 Timing Requirements
    9. 6.9 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Interface Circuits
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Analog Inputs and Input Buffer
      2. 8.3.2  Amplitude and Phase Imbalance Correction
      3. 8.3.3  Over-Range Detection
      4. 8.3.4  Input Clock Divider
      5. 8.3.5  SYSREF Detection Gate
      6. 8.3.6  Serial Differential Output Drivers
        1. 8.3.6.1 De-Emphasis Equalization
        2. 8.3.6.2 Serial Lane Inversion
      7. 8.3.7  ADC Core Calibration
      8. 8.3.8  Data Format
      9. 8.3.9  JESD204B Supported Features
      10. 8.3.10 JESD204B Interface
      11. 8.3.11 Transport Layer Configuration
        1. 8.3.11.1 Lane Configuration
        2. 8.3.11.2 Frame Format
        3. 8.3.11.3 ILA Information
      12. 8.3.12 Test Pattern Sequences
      13. 8.3.13 JESD204B Link Initialization
        1. 8.3.13.1 Frame Alignment
        2. 8.3.13.2 Code Group Synchronization
      14. 8.3.14 SPI
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down and Sleep Modes
    5. 8.5 Register Map
      1. 8.5.1 Register Descriptions
        1. 8.5.1.1  CONFIG_A (address = 0x0000) [reset = 0x3C]
          1. Table 6. CONFIG_A
        2. 8.5.1.2  DEVICE CONFIG (address = 0x0002) [reset = 0x00]
          1. Table 7. DEVICE CONFIG
        3. 8.5.1.3  CHIP_TYPE (address = 0x0003 ) [reset = 0x03]
          1. Table 8. CHIP_TYPE
        4. 8.5.1.4  CHIP_ID (address = 0x0005, 0x0004) [reset = 0x00, 0x1B]
          1. Table 9. CHIP_ID
        5. 8.5.1.5  CHIP_VERSION (address =0x0006) [reset = 0x00]
          1. Table 10. CHIP_VERSION
        6. 8.5.1.6  VENDOR_ID (address = 0x000D, 0x000C) [reset = 0x04, 0x51]
          1. Table 11. VENDOR_ID
        7. 8.5.1.7  SPI_CFG (address = 0x0010 ) [reset = 0x01]
          1. Table 12. SPI_CFG
        8. 8.5.1.8  OM1 (Operational Mode 1) (address = 0x0012) [reset = 0xC1]
          1. Table 13. OM1 (Operational Mode 1)
        9. 8.5.1.9  OM2 (Operational Mode 2) (address = 0x0013) [reset = 0x20]
          1. Table 14. OM2 (Operational Mode 2)
        10. 8.5.1.10 IMB_ADJ (Imbalance Adjust) (address = 0x0014) [reset = 0x00]
          1. Table 15. IMB_ADJ (Imbalance Adjust)
        11. 8.5.1.11 OVR_EN (Over-Range Enable) (address = 0x003A) [reset = 0x00]
          1. Table 16. OVR_EN (Over-Range Enable)
        12. 8.5.1.12 OVR_HOLD (Over-Range Hold) (address = 0x003B) [reset = 0x00]
          1. Table 17. OVR_HOLD (Over-Range Hold)
        13. 8.5.1.13 OVR_TH (Over-Range Threshold) (address = 0x003C) [reset = 0x00]
          1. Table 18. OVR_TH (Over-Range Threshold)
        14. 8.5.1.14 DC_MODE (DC Offset Correction Mode) (address = 0x003D) [reset = 0x00]
          1. Table 19. DC_MODE (DC Offset Correction Mode)
        15. 8.5.1.15 SER_CFG (Serial Lane Transmitter Configuration) (address = 0x0047) [reset = 0x00]
          1. Table 20. SER_CFG (Serial Lane Transmitter Configuration)
        16. 8.5.1.16 JESD_CTRL1 (JESD Configuration Control 1) (address = 0x0060) [reset = 0x7F]
          1. Table 21. JESD_CTRL1 (JESD Configuration Control 1)
        17. 8.5.1.17 JESD_CTRL2 (JESD Configuration Control 2) (address = 0x0061) [reset = 0x00]
          1. Table 22. JESD_CTRL2 (JESD Configuration Control 2)
        18. 8.5.1.18 JESD_RSTEP (JESD Ramp Pattern Step) (address = 0x0063, 0x0062) [reset = 0x00, 0x01]
          1. Table 23. JESD_RSTEP (JESD Ramp Pattern Step)
        19. 8.5.1.19 SER_INV (Serial Lane Inversion Control) (address = 0x0064) [reset = 0x00]
          1. Table 24. SER_INV (Serial Lane Inversion Control)
        20. 8.5.1.20 JESD_STATUS (JESD Link Status) (address = 0x006C) [reset = N/A]
          1. Table 25. JESD_STATUS (JESD Link Status)
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Optimizing Converter Performance
        1. 9.1.1.1 Internal Noise Sources
        2. 9.1.1.2 External Noise Sources
      2. 9.1.2 Analog Input Considerations
        1. 9.1.2.1 Differential Analog Inputs and Full Scale Range
        2. 9.1.2.2 Analog Input Network Model
        3. 9.1.2.3 Input Bandwidth
        4. 9.1.2.4 Driving the Analog Input
        5. 9.1.2.5 Clipping and Over-Range
      3. 9.1.3 CLKIN, SYSREF, and SYNCb Input Considerations
        1. 9.1.3.1 Driving the CLKIN+ and CLKIN– Input
        2. 9.1.3.2 Driving the SYSREF Input
        3. 9.1.3.3 SYSREF Signaling
        4. 9.1.3.4 SYSREF Timing
        5. 9.1.3.5 Effectively Using the Detection Gate Feature
        6. 9.1.3.6 Driving the SYNCb Input
      4. 9.1.4 Output Serial Interface Considerations
        1. 9.1.4.1 Output Serial-Lane Interface
        2. 9.1.4.2 Voltage Swing and De-Emphasis Optimization
        3. 9.1.4.3 Minimizing EMI
      5. 9.1.5 JESD204B System Considerations
        1. 9.1.5.1 Frame and LMFC Clock Alignment Procedure
        2. 9.1.5.2 Link Interruption
        3. 9.1.5.3 Clock Configuration Examples
      6. 9.1.6 SPI
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Design
    2. 10.2 Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.1.1.2 External Noise Sources

Noise sources external to the ADC device that impact the overall system performance through the ADC include: 1) Analog Input Signal Path noise, 2) Sampling Clock Signal Path Noise, 3) Supply Noise

Analog input signal path noise comes from devices in the signal path prior to the ADC and enters through the analog input (VIN+/-). An anti-aliasing filter must be included in front of the ADC to limit the noise bandwidth and prevent the aliasing of noise into any band of interest. Sampling clock signal path noise enters through the sampling clock input (CLKIN+/-) and adds noise similar to the Aperture Jitter. External clock jitter can be minimized by using high quality clock sources and jitter cleaners (PLLs) as well as bandpass filters at the clock input.

The total clock jitter (TJitter), including the aperture jitter of the ADC and external clock noise can be calculated with Equation 3 and applied to Equation 1 and Equation 2 to determine the system impact. Figure 59 shows the simulated impact on the SNR of the ADC31JB68 output spectrum for a given total jitter and input signal frequency.

Equation 3. ADC31JB68 Eq02_Tjitter_slase60.gif
ADC31JB68 SNR_vs_Jitter.gifFigure 59. SNR Limit Due to Total Jitter of Sampling Clock With a -1 dBFS Input Signal

Additional noise may couple to the clock path through power supplies. Take care to provide a very-low noise power supply and isolated supply return path to minimize noise added to the supply. Spurious noise added to the clock path results in symmetrical, modulated spurs around large input signals. These spurs have a constant magnitude in units of dB relative to the input signal amplitude or carrier, [dBc].