JAJSOF6 April   2022 LM5013-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 Pin Configuration and Functions
  6. 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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Control Architecture
      2. 7.3.2  Internal VCC Regulator and Bootstrap Capacitor
      3. 7.3.3  Regulation Comparator
      4. 7.3.4  Internal Soft Start
      5. 7.3.5  On-Time Generator
      6. 7.3.6  Current Limit
      7. 7.3.7  N-Channel Buck Switch and Driver
      8. 7.3.8  Schottky Diode Selection
      9. 7.3.9  Enable/Undervoltage Lockout (EN/UVLO)
      10. 7.3.10 Power Good (PGOOD)
      11. 7.3.11 Thermal Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
      4. 7.4.4 Sleep Mode
  8. 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 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Switching Frequency (RRON)
        3. 8.2.2.3 Buck Inductor (LO)
        4. 8.2.2.4 Schottky Diode (DSW)
        5. 8.2.2.5 Output Capacitor (COUT)
        6. 8.2.2.6 Input Capacitor (CIN)
        7. 8.2.2.7 Type 3 Ripple Network
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Compact PCB Layout for EMI Reduction
      2. 10.1.2 Feedback Resistors
    2. 10.2 Layout Example
      1. 10.2.1 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 サポート・リソース
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, 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

8.2.2.2 Switching Frequency (RRON)

The switching frequency of the LM5013-Q1 is set by the on-time programming resistor placed at RRON. As shown by Equation 7, a standard 100-kΩ, 1% resistor sets the switching frequency at 300 kHz.

Equation 7. GUID-08230912-1499-4274-B350-60FFB99B35F1-low.gif

Note that at very low duty cycles, the 50-ns minimum controllable on time of the high-side MOSFET, tON(min), limits the maximum switching frequency. In CCM, tON(min) limits the voltage conversion step-down ratio for a given switching frequency. Use Equation 8 to calculate the minimum controllable duty cycle.

Equation 8. GUID-03E309F3-328E-498B-81F1-7B0DD28F31C8-low.gif

Ultimately, the choice of switching frequency for a given output voltage affects the available input voltage range, solution size, and efficiency. Use Equation 9 to calculate the maximum supply voltage for a given tON(min) before switching frequency reduction occurs.

Equation 9. GUID-60B1026D-BA30-4A60-AE6A-53DB324349F2-low.gif