SLOSEB6D February   2025  – November 2025 LMH13000

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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 for Low-Current Mode, MODE = 0
    6. 5.6 Electrical Characteristics for High-Current Mode, MODE = 1
    7. 5.7 Typical Characteristics
    8. 5.8 Parameter Measurement Information
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Constant Current (ICC)
      2. 6.3.2 Propagation Delay With Temperature
        1. 6.3.2.1 Calibration of Propagation Delay With Temperature
        2. 6.3.2.2 Start Pulse Directly From IOUT
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Optical Time-of-Flight System
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
      2. 7.2.2 Automatic Power-Control Loop Using the LMH13000
    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 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.2.2 Start Pulse Directly From IOUT

For applications that require even higher accuracy or do not have the ability to calibrate across temperature, the following circuit technique enables high-accuracy start-pulse generation by directly monitoring the laser stage. The laser current pulse generates the start signal for time-of-flight measurement. Resistor RDAMP in series with the laser acts as a current sensing element. The voltage drop across the resistor is converted to differential and provides the start-of-pulse signal as follows.

LMH13000 Laser Diode Pulse Generation for Time-of-Flight Measurement Figure 6-2 Laser Diode Pulse Generation for Time-of-Flight Measurement
LMH13000 Start Pulse, EP Signal, and Laser Cathode Voltage vs Time Figure 6-3 Start Pulse, EP Signal, and Laser Cathode Voltage vs Time

This method removes the requirement for propagation delay calibration of the LMH13000 laser driver. The same configuration also drives both a 100Ω input impedance LVDS driver and any other high input impedance I/O driver.