SNOSDC1A June   2024  – October 2024 LMH1229 , LMH1239

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements for Serial Management (SM) Bus Interface
    7. 5.7 Timing Requirements for Serial Parallel Interface (SPI) Interface
    8. 5.8 Typical Characteristics
      1. 5.8.1 TX Characteristics
      2. 5.8.2 RX Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 4-Level Input Pins and Thresholds
      2. 6.3.2 Input and Output Signal Flow Control
        1. 6.3.2.1 Input Mux Selection (LMH1239 Only)
        2. 6.3.2.2 Output Mux and SDI_OUT Selection
      3. 6.3.3 Input Carrier Detect
      4. 6.3.4 Adaptive Cable Equalizer (SDI_IN±, SDI_IN1±)
      5. 6.3.5 Clock and Data (CDR) Recovery
      6. 6.3.6 CDR Loop Bandwidth Control
      7. 6.3.7 Output Function Control
      8. 6.3.8 Output Driver Control
        1. 6.3.8.1 Line-Side 75Ω Output Cable Driver (SDI_OUT±)
          1. 6.3.8.1.1 Output Amplitude (VOD)
          2. 6.3.8.1.2 Output Pre-Emphasis
          3. 6.3.8.1.3 Output Slew Rate
          4. 6.3.8.1.4 Output Polarity Inversion
        2. 6.3.8.2 Host-Side 100Ω Output Driver (OUT0±, OUT1±)
      9. 6.3.9 Debug and Diagnostic Features
        1. 6.3.9.1 Internal Eye Opening Monitor (EOM)
        2. 6.3.9.2 PRBS Generator, Error Checker, and Error Injector
        3. 6.3.9.3 Status Indicators and Interrupts
          1. 6.3.9.3.1 LOCK_N (Lock Indicator)
          2. 6.3.9.3.2 CD_N (Carrier Detect)
          3. 6.3.9.3.3 Cable Fault Detection (SDI_OUT+ Only)
          4. 6.3.9.3.4 INT_N (Interrupt)
        4. 6.3.9.4 Additional Programmability
          1. 6.3.9.4.1 Cable EQ Index (CEI)
          2. 6.3.9.4.2 Digital MUTEREF
    4. 6.4 Device Functional Modes
      1. 6.4.1 System Management Bus (SMBus) Mode
        1. 6.4.1.1 SMBus Read and Write Transaction
          1. 6.4.1.1.1 SMBus Write Operation Format
          2. 6.4.1.1.2 SMBus Read Operation Format
      2. 6.4.2 Serial Peripheral Interface (SPI) Mode
        1. 6.4.2.1 SPI Read and Write Transactions
          1. 6.4.2.1.1 SPI Write Transaction Format
          2. 6.4.2.1.2 SPI Read Transaction Format
        2. 6.4.2.2 SPI Daisy Chain
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 SMPTE Requirements and Specifications
      2. 7.1.2 Optimizing the Time to Adapt and Lock
      3. 7.1.3 Optimized Loop Bandwidth Settings for Diagnostic or Cascade Applications
      4. 7.1.4 LMH1229 and LMH1297 (EQ Mode) Pin-to-Pin Compatibility
    2. 7.2 Typical Application
      1. 7.2.1 Cable Equalizer With Loop-Through
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Cable Equalizer With Redundant SDI Input (LMH1239 only)
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
        3. 7.2.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Board Stack-Up and Ground References
        2. 7.4.1.2 High-Speed PCB Trace Routing and Coupling
          1. 7.4.1.2.1 SDI_IN± and SDI_OUT±:
          2. 7.4.1.2.2 OUT0± and OUT1±:
        3. 7.4.1.3 Anti-Pads
        4. 7.4.1.4 BNC Connector Layout and Routing
        5. 7.4.1.5 Power Supply and Ground Connections
        6. 7.4.1.6 Footprint Recommendations
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.1.2 High-Speed PCB Trace Routing and Coupling

Observe the following general high-speed recommendations for high-speed trace routing:

  • For differential pairs, maintain a uniform width and gap for each differential pair where possible. When traces must diverge (for example, due to AC-coupling capacitors), ensure that the traces branch out or merge uniformly.
  • To prevent reflections due to trace routing, ensure that trace bends are at most 45°. Implement right angle bends with at least two 45° corners. Radial bends are ideal.
  • Avoid using signal vias. If signal vias must be used, a return path (GND) via must be placed near the signal via to provide a consistent ground reference and minimize impedance discontinuities.
  • Avoid via stubs by back-drilling as necessary.