ZHCSKE0B March   2017  – October 2019 LMH1208

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     简化方框图
  4. 4 修订历史记录
  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. 11器件和文档支持
    1. 11.1 文档支持
      1. 11.1.1 相关文档
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 出口管制提示
    7. 11.7 Glossary
  12. 12机械、封装和可订购信息
    1. 12.1 Package Option Addendum
      1. 12.1.1 Packaging Information
      2. 12.1.2 Tape and Reel Information

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

7.3.4 Continuous Time Linear Equalizer (CTLE)

The LMH1208 has a continuous time linear equalizer (CTLE) block for IN0. The CTLE compensates for frequency-dependent loss due to the transmission media prior to the device input. The CTLE accomplishes this by applying variable gain to the input signal, thereby boosting higher frequencies more than lower frequencies. The CTLE block extends the signal bandwidth, restores the signal amplitude, and reduces ISI caused by the transmission medium.

IN0 has an on-chip 100-Ω termination and is designed for AC coupling, requiring a 4.7-μF, AC-coupling capacitor for minimizing base-line wander. The PCB equalizer can compensate up to 20 inches of board trace at data rates up to 11.88 Gbps. There is one adapt mode for IN0: AM0 manual mode. In AM0 manual mode, fixed EQ boost settings are applied through user-programmable control.

The HOST_EQ0 pin determines the IN0 adapt mode and EQ boost level. For normal operation, HOST_EQ0 = F is recommended. HOST_EQ0 pin logic settings are shown in Table 4. These HOST_EQ0 pin settings can be overridden by register control. For more information, refer to the LMH1228 and LMH1208 Programming Guide (SNAU206).

Table 4. HOST_EQ0 Pin EQ Settings

HOST_EQ0(1) IN0± EQ BOOST RECOMMENDED BOARD
TRACE IN0±(2)
H, F All Rates: AM0 Manual Mode, EQ=0x00 < 1 inch
R All Rates: AM0 Manual Mode, EQ=0x80 10-15 inches
L All Rates: AM0 Manual Mode, EQ=0x90 20 inches
(1) The HOST_EQ0 pin is also used to set OUT0 VOD and de-emphasis values. See Host-Side 100-Ω Output Driver (OUT0±) for more information.
(2) Recommended board trace at 11.88 Gbps.