JAJSKE1 October   2021 LM61430-Q1

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Characteristics
    7. 7.7 Systems Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  EN/SYNC Uses for Enable and VIN UVLO
      2. 8.3.2  EN/SYNC Pin Uses for Synchronization
      3. 8.3.3  Clock Locking
      4. 8.3.4  Adjustable Switching Frequency
      5. 8.3.5  PGOOD Output Operation
      6. 8.3.6  Internal LDO, VCC UVLO, and BIAS Input
      7. 8.3.7  Bootstrap Voltage and VCBOOT-UVLO (CBOOT Pin)
      8. 8.3.8  Adjustable SW Node Slew Rate
      9. 8.3.9  Spread Spectrum
      10. 8.3.10 Soft Start and Recovery From Dropout
      11. 8.3.11 Output Voltage Setting
      12. 8.3.12 Overcurrent and Short Circuit Protection
      13. 8.3.13 Thermal Shutdown
      14. 8.3.14 Input Supply Current
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Standby Mode
      3. 8.4.3 Active Mode
        1. 8.4.3.1 Auto Mode - Light-Load Operation
          1. 8.4.3.1.1 Diode Emulation
          2. 8.4.3.1.2 Frequency Reduction
        2. 8.4.3.2 FPWM Mode - Light-Load Operation
          1. 8.4.3.2.1 CCM Mode
        3. 8.4.3.3 Minimum On Time (High Input Voltage) Operation
        4. 8.4.3.4 Dropout
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Choosing the Switching Frequency
        2. 9.2.2.2  Setting the Output Voltage
        3. 9.2.2.3  Inductor Selection
        4. 9.2.2.4  Output Capacitor Selection
        5. 9.2.2.5  Input Capacitor Selection
        6. 9.2.2.6  BOOT Capacitor
        7. 9.2.2.7  BOOT Resistor
        8. 9.2.2.8  VCC
        9. 9.2.2.9  BIAS
        10. 9.2.2.10 CFF and RFF Selection
        11. 9.2.2.11 External UVLO
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Thermal Considerations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 サポート・リソース
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.2.11 External UVLO

In some cases, an input UVLO level different than that provided internal to the device is needed. This can be accomplished by using the circuit shown in Figure 9-3. The input voltage at which the device turns on is designated VON while the turn-off voltage is VOFF. First, a value for RENB is chosen in the range of 10 kΩ to 100 kΩ, then Equation 13 is used to calculate RENT and VOFF. RENB is typically set based on how much current this voltage divider should consume. RENB can be calculated using Equation 12.

Equation 12. GUID-DEF40710-F288-49B5-B0E6-78F30E0EEE7A-low.gif
GUID-41C78047-EB24-403E-965E-E51E4BA2DC84-low.gifFigure 9-3 UVLO Using EN
Equation 13. GUID-73D93146-78BE-43D9-B761-F50EF749E8AB-low.gif

where

  • VON = VIN turn-on voltage
  • VOFF = VIN turn-off voltage
  • IDIVIDER = Voltage divider current