SNLS545E March   2017  – July 2022 LMH1297

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and 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
    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
      3. 9.1.3 Optimized Loop Bandwidth Settings for Arria 10 FPGA Applications
    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. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information
8.3.9.1.1 Output Amplitude (VOD)

In CD mode (EQ/CD_SEL = H), SDI_IO is enabled as an SDI cable driver output. In either CD or EQ mode, SDI_OUT is an SDI cable driver output. In EQ mode, SDI_OUT serves as a loop-through output, and in CD mode, SDI_OUT serves as a secondary cable driver output.

SDI_IO (in CD mode) and SDI_OUT are designed for transmission across 75-Ω single-ended impedance. The nominal SDI cable driver output amplitude (VOD) is 800 mVp-p single-ended. In the presence of long output cable lengths or crosstalk, the SDI_VOD pin can be used to optimize the cable driver output with respect to the nominal amplitude. Table 8-8 details VOD settings that can be applied to both SDI_IO and SDI_OUT. The SDI_VOD pin can be overridden through register control. In addition, the nominal VOD amplitude can be changed by register control. For more information, refer to the LMH1297 Programming Guide.

Table 8-8 SDI_VOD Settings for Line-Side Output Amplitude
SDI_VODDESCRIPTION
Habout +5% of nominal
F800 mVp-p (nominal)
Rabout +10% of nominal
Labout –5% of nominal