SNOSD74B May   2019  – January 2020 LMG1025-Q1

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Typical (Simplified) System Diagram
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input Stage
      2. 7.3.2 Output Stage
      3. 7.3.3 Bias Supply and Under Voltage Lockout
      4. 7.3.4 Overtemperature Protection (OTP)
    4. 7.4 Device Functional Modes
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Handling Ground Bounce
        2. 8.2.2.2 Creating Nanosecond Pulse
      3. 8.2.3 VDD and Overshoot
      4. 8.2.4 Operating at Higher Frequency
      5. 8.2.5 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Gate Drive Loop Inductance and Ground Connection
      2. 10.1.2 Bypass Capacitor
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Application Curves

LMG1025-Q1 EVM is used to take application waveforms. This EVM has LDO, input buffer, GaN FET, and load resistor. It shows the switching performance of the LMG1025-Q1 when equivalent laser diode current is switched. Figure 11 and Figure 12 show VDD turn-on and turn-off delay in an application-like set-up. System designer need to make sure that these delays are acceptable in their designs. LIDAR design needs to pulse the laser diode for very short duration. Figure 13 shows how LMG1025-Q1 can not only handle nano-second pulse at its input but also can produce a nano-second pulse at the output while driving a reasonably sized GaN FET that has 3.2nC of typical total gate charge. Figure 13 also shows very small, e.g. less than 3 ns, rising and falling propagation delay of LMG1025-Q1. Figure 14 shows drive strength of LMG1025-Q1. It shows how LMG1025-Q1 can achieve sub-nano second rise and fall time, which is very important for LIDAR applicatoins.

LMG1025-Q1 start_time.gifFigure 11. Startup Time
LMG1025-Q1 PW_PROP_DELAY.gifFigure 13. Input pulse width and propagation delays
LMG1025-Q1 shutoff_time.gifFigure 12. Shutdown Time
LMG1025-Q1 RISE_FALL.gifFigure 14. Rise and fall time