ZHCSDJ6E February   2015  – June 2018 LMH1218

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
    1.     Device Images
      1.      简化 SPI 电路原理图
  4. 修订历史记录
  5. Pin Configuration and Functions
    1.     Pin Descriptions – SPI Mode/ Mode_SEL = 1 kΩ to VDD
    2.     Pin Descriptions – SMBUS Mode/ MODE_SEL = 1 kΩ to GND
  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) Bus Interface AC Timing Specifications
    8. 6.8 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Loss of Signal Detector
      2. 7.3.2 Continuous Time Linear Equalizer (CTLE)
      3. 7.3.3 2:1 Multiplexer
      4. 7.3.4 Clock and Data Recovery
      5. 7.3.5 Eye Opening Monitor (EOM)
      6. 7.3.6 Fast EOM
        1. 7.3.6.1 SMBus Fast EOM Operation
        2. 7.3.6.2 SPI Fast EOM Operation
      7. 7.3.7 LMH1218 Device Configuration
        1. 7.3.7.1 MODE_SEL
        2. 7.3.7.2 ENABLE
        3. 7.3.7.3 LOS_INT_N
        4. 7.3.7.4 LOCK
        5. 7.3.7.5 SMBus MODE
        6. 7.3.7.6 SMBus READ/WRITE Transaction
        7. 7.3.7.7 SPI Mode
          1. 7.3.7.7.1 SPI READ/WRITE Transaction
          2. 7.3.7.7.2 SPI Write Transaction Format
          3. 7.3.7.7.3 SPI Read Transaction Format
        8. 7.3.7.8 SPI Daisy Chain
          1. 7.3.7.8.1 SPI Daisy Chain Write Example
          2. 7.3.7.8.2 SPI Daisy Chain Write Read Example
            1. 7.3.7.8.2.1 SPI Daisy Chain Length of Daisy Chain Illustration
      8. 7.3.8 Power-On Reset
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
    6. 7.6 Register Maps
      1. 7.6.1 Global Registers
      2. 7.6.2 Receiver Registers
      3. 7.6.3 CDR Registers
      4. 7.6.4 Transmitter Registers
  8. Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 General Guidance for All Applications
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Do's and Don'ts
    4. 8.4 Initialization Set Up
      1. 8.4.1 Selective Data Rate Lock
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Solder Profile
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 开发支持
    2. 11.2 文档支持
      1. 11.2.1 相关文档
    3. 11.3 接收文档更新通知
    4. 11.4 社区资源
    5. 11.5 商标
    6. 11.6 静电放电警告
    7. 11.7 术语表
  12. 12机械、封装和可订购信息

Loss of Signal Detector

The LMH1218 supports two high speed differential input ports, with internal 100-Ω terminations. The inputs must be AC coupled. The external AC coupling capacitor value should take into account the pathological low frequency content. For most applications, the RC time constant of 4.7 µF AC coupling capacitor plus the 50-Ω termination resistor is capable of handing the pathological video pattern's low frequency content.

The signal detect circuit is designed to assert when data traffic with a certain minimum amplitude is present at the input of the device. It is also designed to de-assert, or remain de-asserted, when there is noise below certain amplitude at the input to the device.

The LMH1218 has two signal detect circuits, one for each input. Each signal detect threshold can be set independently. By default, both signal detects are powered on. The user selects IN1 or IN0 through SMBus/SPI interface.