SNLS531B April   2016  – June 2018 LMH0324

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      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 AC Timing Specifications
    7. 6.7 Serial Parallel Interface (SPI) AC 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 Configuration Pins
      2. 7.3.2 Carrier Detect
      3. 7.3.3 Adaptive Cable Equalizer
      4. 7.3.4 Launch Amplitude
      5. 7.3.5 Input-Output Mux Selection
      6. 7.3.6 Output Function Control
      7. 7.3.7 Output Driver Amplitude and De-Emphasis Control
      8. 7.3.8 Additional Programmability
        1. 7.3.8.1 Cable Length Indicator (CLI)
        2. 7.3.8.2 Digital MUTEREF
    4. 7.4 Device Functional Modes
      1. 7.4.1 System Management Bus (SMBus) Mode
        1. 7.4.1.1 SMBus Read and Write Transactions
          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
          1. 7.4.2.1.1 SPI Write Transaction Format
          2. 7.4.2.1.2 SPI Read Transaction Format
        2. 7.4.2.2 SPI Daisy Chain
    5. 7.5 LMH0324 Register Map
      1. 7.5.1 Share Register Page
      2. 7.5.2 CableEQ/Drivers Register Page
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 General Guidance for SMPTE Applications
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Recommended VOD and DE Register Settings
      4. 8.2.4 Application Performance Plots
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RTW|24
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.2 Carrier Detect

An internal Carrier Detector circuit is used to monitor the presence or absence of the input signal. When the input signal amplitude exceeds the carrier detector’s threshold, adaptation is activated, and CD_N is pulled low at the end of adaptation. When the input signal amplitude is below the carrier detector’s threshold, input equalization circuitry is powered down and the CD_N is pulled high to indicate absence of input signal. The LMH0324 high gain adaptive cable equalizer supports long cable reach. As a result, the carrier detector threshold is sensitive, and system designers need to pay close attention to the PCB layout to avoid excessive crosstalk from interfering with the carrier detection.

In the absence of input signal, the LMH0324 automatically goes into Power Save Mode to conserve power consumption. When valid signal is detected, the LMH0324 automatically exits the Power Save Mode and returns to the normal operating mode. An LED can be connected to CD_N through a current limiting resistor to provide visual indication of the carrier detection.