SNLS569C March   2017  – May 2020 LMH1208

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Block Diagram
  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
    6. 6.6 Recommended SMBus Interface Timing Specifications
    7. 6.7 Serial Parallel Interface (SPI) Timing Specifications
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 4-Level Input Pins and Thresholds
      2. 7.3.2 OUT0_SEL and SDI_OUT2_SEL Control
      3. 7.3.3 Input Signal Detect
      4. 7.3.4 Continuous Time Linear Equalizer (CTLE)
      5. 7.3.5 Output Driver Control
        1. 7.3.5.1 Line-Side Output Cable Driver (SDI_OUT1+, SDI_OUT2+)
          1. 7.3.5.1.1 Output Amplitude (VOD)
          2. 7.3.5.1.2 Output Pre-Emphasis
          3. 7.3.5.1.3 Output Slew Rate
          4. 7.3.5.1.4 Output Polarity Inversion
        2. 7.3.5.2 Host-Side 100-Ω Output Driver (OUT0±)
      6. 7.3.6 Status Indicators and Interrupts
        1. 7.3.6.1 SD_N (Signal Detect)
        2. 7.3.6.2 INT_N (Interrupt)
    4. 7.4 Device Functional Modes
      1. 7.4.1 System Management Bus (SMBus) Mode
        1. 7.4.1.1 SMBus Read and Write Transaction
          1. 7.4.1.1.1 SMBus Write Operation Format
          2. 7.4.1.1.2 SMBus Read Operation Format
      2. 7.4.2 Serial Peripheral Interface (SPI) Mode
        1. 7.4.2.1 SPI Read and Write Transactions
        2. 7.4.2.2 SPI Write Transaction Format
        3. 7.4.2.3 SPI Read Transaction Format
        4. 7.4.2.4 SPI Daisy Chain
    5. 7.5 Register Maps
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 SMPTE Requirements and Specifications
      2. 8.1.2 LMH1208 and LMH1228 Compatibility
    2. 8.2 Typical Applications
      1. 8.2.1 Dual Cable Driver
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Distribution Amplifier
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Board Stack-Up and Ground References
      2. 10.1.2 High-Speed PCB Trace Routing and Coupling
      3. 10.1.3 Anti-Pads
      4. 10.1.4 BNC Connector Layout and Routing
      5. 10.1.5 Power Supply and Ground Connections
      6. 10.1.6 Footprint Recommendations
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Export Control Notice
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Package Option Addendum
      1. 12.1.1 Packaging Information
      2. 12.1.2 Tape and Reel Information

Package Options

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

7.4.2.3 SPI Read Transaction Format

A SPI read transaction is 34 bits per device and consists of two 17-bit frames. The first 17-bit read transaction frame shifts in the address to be read, followed by a dummy transaction second frame to shift out 17-bit read data. The R/W bit is 1'b for the read transaction, as shown in Figure 3.

The first 17 bits from the read transaction specifies 1-bit of R/W and 8-bits of address A7-A0 in the first 8 bits. The eight 1’s following the address are ignored. The second dummy transaction acts like a read operation on address 0xFF and needs to be ignored. However, the transaction is necessary in order to shift out the read data D7-D0 in the last 8 bits of the MISO output. As with the SPI Write, the prime values on MISO during the first 16 clocks are listed as don’t care for this portion of the transaction. The values shifted out on MISO during the last 17 clocks reflect the read address and 8-bit read data for the current transaction.

LMH1208 td04_signal_timing_spi_read_snls515.gifFigure 16. Signal Timing for a SPI Read Transaction