JAJSF12A March   2018  – January 2024 LMR14010A

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  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 Fixed Frequency PWM Control
      2. 6.3.2 Bootstrap Voltage (CB)
      3. 6.3.3 Setting the Output Voltage
      4. 6.3.4 Enable ( SHDN ) and VIN Undervoltage Lockout
      5. 6.3.5 Current Limit
      6. 6.3.6 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Continuous Conduction Mode
      2. 6.4.2 Eco-mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
        1. 7.2.1.1 Step-By-Step Design Procedure
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 Output Inductor Selection
        3. 7.2.2.3 Output Capacitor Selection
        4. 7.2.2.4 Schottky Diode Selection
        5. 7.2.2.5 Input Capacitor Selection
        6. 7.2.2.6 Bootstrap Capacitor Selection
      3. 7.2.3 Application Performance Curves
    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 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 ドキュメントの更新通知を受け取る方法
    3. 8.3 サポート・リソース
    4. 8.4 Trademarks
    5. 8.5 静電気放電に関する注意事項
    6. 8.6 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.4.1 Continuous Conduction Mode

The LMR14010A steps the input voltage down to a lower output voltage. In continuous conduction mode (when the inductor current never reaches zero at steady state), the buck regulator operates in two cycles. The power switch is connected between VIN and SW. In the first cycle of operation the transistor is closed and the diode is reverse biased. Energy is collected in the inductor, the load current is supplied by COUT and the current through the inductor is rising. During the second cycle the transistor is open and the diode is forward biased due to the fact that the inductor current cannot instantaneously change direction. The energy stored in the inductor is transferred to the load and output capacitor. The ratio of these two cycles determines the output voltage. The output voltage is defined approximately as: D = VOUT/VIN and D' = (1-D) where D is the duty cycle of the switch, D and D' will be required for design calculations.