JAJU648A November   2018  – April 2022 TLV3601 , TLV3601-Q1 , TLV3603 , TLV3603-Q1

 

  1.   概要
  2.   Resources
  3.   特長
  4.   アプリケーション
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Amplifier and Comparator
      2. 2.2.2 Digital Processing and Control
      3. 2.2.3 Optical Components
        1. 2.2.3.1 Laser Driver and Laser Diode
        2. 2.2.3.2 Photodiode
      4. 2.2.4 Power Supply
    3. 2.3 Highlighted Products
      1. 2.3.1 OPA858 Operational Amplifier
      2. 2.3.2 TLV3501 and TLV3601/3 High-Speed Comparators
      3. 2.3.3 TDC7201 Time-to-Digital Converter
    4. 2.4 System Design Theory
      1. 2.4.1 Transimpedance Amplifier
        1. 2.4.1.1 Bandwidth
        2. 2.4.1.2 Stability Considerations
        3. 2.4.1.3 Noise Performance
      2. 2.4.2 Time-of-Flight Measurement
      3. 2.4.3 Simulations
        1. 2.4.3.1 Bandwidth Simulation
        2. 2.4.3.2 Noise Simulation
        3. 2.4.3.3 OPA858 Loop-Gain and Phase Margin Simulation
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
      1. 3.1.1 Hardware
      2. 3.1.2 Software
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
        1. 3.2.1.1 Getting Started: System Setup
          1. 3.2.1.1.1 Laser-Driver Setup
          2. 3.2.1.1.2 Receiver and Optical Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Verification and Measured Performance
          1. 3.2.2.1.1 Pulse Response Measurements
            1. 3.2.2.1.1.1 Pulse Response Settling
            2. 3.2.2.1.1.2 Pulse Response vs Output Pulse Width
            3. 3.2.2.1.1.3 Rise and Fall Time
            4. 3.2.2.1.1.4 Overdriven Response
          2. 3.2.2.1.2 Time-of-Flight Test
          3. 3.2.2.1.3 Time-of-Flight Measurement Error Sources
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
  10. 5Related Documentation
    1. 5.1 Trademarks
  11. 6About the Author
  12. 7Revision History

2.4.1.3 Noise Performance

For the selected OPA858 amplifier circuit design, the total calculated noise without any post filtering results in an input RMS current noise of 132 nArms. This value determines the smallest signal that can be measured without averaging from the OPA858, and at the output yields an output voltage noise of 1.3 mVrms. The circuit noise can be improved by adding a post filter set at or higher than the frequency of the transimpedance bandwidth. Using a simple single-pole, low-pass filter set at 260 MHz reduces the input noise of the circuit to 90 nArms, which only lowers the bandwidth slightly to 253 MHz. Even better noise performance can be obtained with higher-order filters; however, for this design the input signal current is significantly higher than 132 nArms and does not require any additional filtering.