ZHCSPP6E May   2008  – July 2024 LMH6518

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  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
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Input Preamplifier
        1. 6.3.1.1 Primary Output Amplifier
        2. 6.3.1.2 Auxiliary Amplifier
      2. 6.3.2 Overvoltage Clamp
      3. 6.3.3 Attenuator
      4. 6.3.4 Digital Control Block
    4. 6.4 Device Functional Modes
      1. 6.4.1 Primary Amplifier
      2. 6.4.2 Auxiliary Output
    5. 6.5 Programming
      1. 6.5.1 Logic Functions
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Oscilloscope Front End
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Settings and ADC SPI Code (ECM)
          2. 7.2.1.2.2 Input and Output Considerations
            1. 7.2.1.2.2.1 Output Swing, Clamping, and Operation Beyond Full Scale
          3. 7.2.1.2.3 Oscilloscope Trigger Applications
        3. 7.2.1.3 Application Curves
      2. 7.2.2 JFET LNA Implementation
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
          1. 7.2.2.2.1 Attenuator Design
        3. 7.2.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 第三方产品免责声明
      2. 8.1.2 Device Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 接收文档更新通知
    4. 8.4 支持资源
    5. 8.5 Trademarks
    6. 8.6 静电放电警告
    7. 8.7 术语表
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.1.1 Design Requirements

An oscilloscope is used to sample signals from millivolts to volts. To make the best use of the limited ADC input range, the oscilloscope input circuitry must have a wide gain range.

In this design example, the LMH6518 is driving an ADC12J2700 and has the following requirements:

  • Common mode voltage = 1.225-V
  • Full scale voltage = 650 mVPP to 800 mVPP
  • Bandwidth = 900-MHz
  • Trigger channel
  • Spurious free dynamic range = 50-dB