SNOSB22D October   2008  – April 2025 LM5574-Q1

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
    6. 5.6 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 Shutdown and Standby
      2. 6.3.2 Current Limit
      3. 6.3.3 Soft Start
      4. 6.3.4 Thermal Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 High Voltage Start-Up Regulator
      2. 6.4.2 Oscillator and Sync Capability
      3. 6.4.3 Error Amplifier and PWM Comparator
      4. 6.4.4 Ramp Generator
      5. 6.4.5 Maximum Duty Cycle and Input Dropout Voltage
      6. 6.4.6 Boost Pin
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Bias Power Dissipation Reduction
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1  Custom Design With WEBENCH® Tools
        2. 7.2.2.2  External Components
        3. 7.2.2.3  R3 (RT)
        4. 7.2.2.4  L1- Inductor
        5. 7.2.2.5  C3- Ramp Capacitor
        6. 7.2.2.6  C9 -Output Capacitor
        7. 7.2.2.7  D1 - Async Diode
        8. 7.2.2.8  C1- Input Capacitor
        9. 7.2.2.9  C8 - Vcc Capacitor
        10. 7.2.2.10 C7 - BST Capacitor
        11. 7.2.2.11 C4 - SS Capacitor
        12. 7.2.2.12 R5, R6 - Feedback Resistor
        13. 7.2.2.13 R1, R2, C2 - SD Pin Components
        14. 7.2.2.14 R4, C5, C6 - Compensation Components
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
      3. 7.4.3 Power Dissipation
      4. 7.4.4 Thermal Considerations
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

5.6 Typical Characteristics

LM5574-Q1 Oscillator Frequency vs RTFigure 5-1 Oscillator Frequency vs RT
LM5574-Q1 Soft-Start Current vs TemperatureFigure 5-3 Soft-Start Current vs Temperature
LM5574-Q1 VCC vs VIN RL = 7kΩFigure 5-5 VCC vs VIN RL = 7kΩ
LM5574-Q1 Demoboard Efficiency vs IOUT and VINFigure 5-7 Demoboard Efficiency vs IOUT and VIN
LM5574-Q1 Oscillator Frequency vs Temperature FOSC = 200kHzFigure 5-2 Oscillator Frequency vs Temperature FOSC = 200kHz
LM5574-Q1 VCC vs ICC VIN = 12VFigure 5-4 VCC vs ICC VIN = 12V
LM5574-Q1 Error Amplifier Gain And Phase AVCL = 101Figure 5-6 Error Amplifier Gain And Phase AVCL = 101