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

9.1.1.1 Internal Noise Sources

The signal to noise ratio of the ADC is limited by the following noise sources inherent to the device: 1) Quantization Noise, 2) Thermal Noise, 3) Sampling Instant Noise (Aperture Jitter). These sources combine together to limit the noise performance of the converter as described by Equation 1. Noise sources external to the ADC can generally be included in this equation as an RMS summation to determine system performance.

Equation 1. ADC31JB68 Eq01_SNR_slase60.gif

Quantization noise is independent of the input signal but does not affect the noise performance of the ADC31JB68 because the SNR limitation of a 16-bit ADC due to quantization noise is 96-dB, well above the SNR of this device. The thermal noise is input independent, spread evenly across the spectrum, and the main limitation for signals with lower frequencies or lower amplitudes.

If quantization and thermal noise is ignored, the fundamental SNR limitation due to aperture jitter can be calculated using Equation 2.

Equation 2. SNRJitter[dBc] = –20 × log(2π × ƒin × Tjitter)

Signals with larger amplitudes and higher frequencies introduce signal dependent sampling instant noise due to the Jitter on the sampling clock edge. This noise includes a broadband component that raises the overall noise spectral density as well as a in-close noise component that is spectrally shaped and concentrates around the signal in the spectrum. The differential clock receiver of the ADC31JB68 has a very-low noise floor and wide bandwidth. Minimizing the aperture jitter requires a sampling clock with a steep edge rate at the zero crossing. Lesser edge rates increase the aperture jitter as demonstrated in Figure 58 which shows the SNR limitation due to aperture jitter as a function of clock edge range and input signal frequency.

ADC31JB68 D006_SLASE60.gifFigure 58. Aperture Jitter vs Input Clock Edge Rate, -1 dBFS Input Signal