ZHCSKF3B April   2017  – October 2019 LMH0397

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     简化方框图
  4. 4 修订历史记录
  5. 5 说明 （续）
  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
    6. 7.6 Recommended SMBus Interface Timing Specifications
    7. 7.7 Serial Parallel Interface (SPI) Timing Specifications
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Equalizer Mode (EQ Mode)
      2. 8.1.2 Cable Driver Mode (CD Mode)
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  4-Level Input Pins and Thresholds
      2. 8.3.2  Equalizer (EQ) and Cable Driver (CD) Mode Control
        1. 8.3.2.1 EQ/CD_SEL Control
        2. 8.3.2.2 OUT0_SEL and SDI_OUT_SEL Control
      3. 8.3.3  Input Carrier Detect
      4. 8.3.4  –6-dB Splitter Mode Launch Amplitude for SDI_IO+ (EQ Mode Only)
      5. 8.3.5  Continuous Time Linear Equalizer (CTLE)
        1. 8.3.5.1 Line-Side Adaptive Cable Equalizer (SDI_IO+ in EQ Mode)
        2. 8.3.5.2 Host-Side Adaptive PCB Trace Equalizer (IN0± in CD Mode)
      6. 8.3.6  Clock and Data (CDR) Recovery
      7. 8.3.7  Internal Eye Opening Monitor (EOM)
      8. 8.3.8  Output Function Control
      9. 8.3.9  Output Driver Control
        1. 8.3.9.1 Line-Side Output Cable Driver (SDI_IO+ in CD Mode, SDI_OUT+ in EQ or CD Mode)
          1. 8.3.9.1.1 Output Amplitude (VOD)
          2. 8.3.9.1.2 Output Pre-Emphasis
          3. 8.3.9.1.3 Output Slew Rate
          4. 8.3.9.1.4 Output Polarity Inversion
        2. 8.3.9.2 Host-Side 100-Ω Output Driver (OUT0± in EQ or CD Mode)
      10. 8.3.10 Status Indicators and Interrupts
        1. 8.3.10.1 LOCK_N (Lock Indicator)
        2. 8.3.10.2 CD_N (Carrier Detect)
        3. 8.3.10.3 INT_N (Interrupt)
      11. 8.3.11 Additional Programmability
        1. 8.3.11.1 Cable EQ Index (CEI)
        2. 8.3.11.2 Digital MUTEREF
    4. 8.4 Device Functional Modes
      1. 8.4.1 System Management Bus (SMBus) Mode
        1. 8.4.1.1 SMBus Read and Write Transaction
          1. 8.4.1.1.1 SMBus Write Operation Format
          2. 8.4.1.1.2 SMBus Read Operation Format
      2. 8.4.2 Serial Peripheral Interface (SPI) Mode
        1. 8.4.2.1 SPI Read and Write Transactions
        2. 8.4.2.2 SPI Write Transaction Format
        3. 8.4.2.3 SPI Read Transaction Format
        4. 8.4.2.4 SPI Daisy Chain
    5. 8.5 Register Maps
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 SMPTE Requirements and Specifications
      2. 9.1.2 Low-Power Optimization in CD Mode
    2. 9.2 Typical Applications
      1. 9.2.1 Bidirectional I/O
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Cable Equalizer With Loop-Through
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Board Stack-Up and Ground References
      2. 11.1.2 High-Speed PCB Trace Routing and Coupling
        1. 11.1.2.1 SDI_IO± and SDI_OUT±
        2. 11.1.2.2 IN0± and OUT0±
      3. 11.1.3 Anti-Pads
      4. 11.1.4 BNC Connector Layout and Routing
      5. 11.1.5 Power Supply and Ground Connections
      6. 11.1.6 Footprint Recommendations
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 器件支持
      1. 12.1.1 开发支持
    2. 12.2 文档支持
      1. 12.2.1 相关文档
    3. 12.3 接收文档更新通知
    4. 12.4 支持资源
    5. 12.5 商标
    6. 12.6 静电放电警告
    7. 12.7 出口管制提示
    8. 12.8 Glossary
  13. 13机械、封装和可订购信息
    1. 13.1 Package Option Addendum
      1. 13.1.1 Packaging Information
      2. 13.1.2 Tape and Reel Information

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

8.3.7 Internal Eye Opening Monitor (EOM)

The LMH0397 has an on-chip eye opening monitor (EOM) that can be used to analyze, monitor, and diagnose the post-equalized waveform, just before the CDR reclocker. The EOM is operational for 2.97 Gbps and higher data rates.

The EOM monitors the post-equalized waveform in a time window that spans one unit interval and a configurable voltage range that spans up to ±400 mV. The time window and voltage range are divided into 64 steps, so the result of the eye capture is a 64 × 64 matrix of hits, where each point represents a specific voltage and phase offset relative to the main data sampler. The number of hits registered at each point must be taken in context with the total number of bits observed at that voltage and phase offset to determine the corresponding probability for that point.

The resulting 64 × 64 matrix produced by the EOM can be processed by software and visualized in a number of ways. Two common ways to visualize this data are shown in Figure 10 and Figure 11. These diagrams depict examples of eye monitor plots implemented by software. The first plot is an example using the EOM data to plot a basic eye using ASCII characters, which can be useful for diagnostic software. The second plot shows the first derivative of the EOM data, revealing the density of hits and the actual waveforms and crossings that comprise the eye.

LMH0397 internal_eye_monitor_input_plot_snls475.pngFigure 10. Internal Input Eye Monitor Plot
LMH0397 internal_eye_monitor_hit_density_plot_snls475.pngFigure 11. Internal Eye Monitor Hit Density Plot

A common measurement performed by the EOM is the horizontal and vertical eye opening. The horizontal eye opening (HEO) represents the width of the post-equalized eye at 0-V differential amplitude, measured in unit intervals or picoseconds (ps). The vertical eye opening (VEO) represents the height of the post-equalized eye, measured midway between the mean zero crossing of the eye. This position in time approximates the CDR sampling phase. HEO and VEO measurements can be read back through register control.