JAJSJ57B May   2020  – January 2022 TPS92200

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 Timing Requirements
    7.     Switching Characteristics
    8. 6.7 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 Peak-Current-Mode PWM Control
      2. 7.3.2 Setting LED Current
      3. 7.3.3 Internal Soft Start
      4. 7.3.4 Input Undervoltage Lockout
      5. 7.3.5 Bootstrap Regulator
      6. 7.3.6 Maximum Duty Cycle
      7. 7.3.7 Overcurrent Protection
        1. 7.3.7.1 High-Side MOSFET Overcurrent Protection
        2. 7.3.7.2 Low-Side MOSFET Sourcing Overcurrent Protection
        3. 7.3.7.3 Low-Side MOSFET Sinking Overcurrent Protection
      8. 7.3.8 Fault Protection
        1. 7.3.8.1 LED Open-Load Protection
        2. 7.3.8.2 LED+ and LED– Short Circuit Protection
        3. 7.3.8.3 LED+ Short Circuit to GND Protection
        4. 7.3.8.4 Sense-Resistor Open-Load Protection
        5. 7.3.8.5 Sense Resistor Short Circuit-to-GND Protection
        6. 7.3.8.6 Overvoltage Protection
        7. 7.3.8.7 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enable and Disable the Device
      2. 7.4.2 TPS92200D1 PWM Dimming
      3. 7.4.3 TPS92200D1 Analog Dimming
      4. 7.4.4 TPS92200D2 Analog Dimming
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 TPS92200D1 12-V Input, 1.5-A, 2-Piece IR LED Driver With Analog Dimming
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Inductor Selection
          2. 8.2.1.2.2 Input Capacitor Selection
          3. 8.2.1.2.3 Output Capacitor Selection
            1. 8.2.1.2.3.1 Sense Resistor Selection
              1. 8.2.1.2.3.1.1 Other External Components Selection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 TPS92200D1 24-V Input, 1-A, 6-Piece WLED Driver With PWM Dimming
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Inductor Selection
          2. 8.2.2.2.2 Input Capacitor Selection
          3. 8.2.2.2.3 Output Capacitor Selection
            1. 8.2.2.2.3.1 Sense Resistor Selection
              1. 8.2.2.2.3.1.1 Other External Components Selection
        3. 8.2.2.3 Application Curves
      3. 8.2.3 5-V Input, 1-A, 1-Piece IR LED Driver With TPS92200D2
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1 Inductor Selection
          2. 8.2.3.2.2 Input Capacitor Selection
          3. 8.2.3.2.3 Output Capacitor Selection
            1. 8.2.3.2.3.1 Sense Resistor Selection
              1. 8.2.3.2.3.1.1 Other External Components Selection
        3. 8.2.3.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 サポート・リソース
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.3.6 Maximum Duty Cycle

For a buck LED driver, the maximum duty cycle is limited by the minimum off time tMIN_OFF and switching frequency. To achieve the maximum brightness when the input voltage is close to output voltage, the TPS92200 device has a mechanism to decrease the switching frequency. This mechanism extends the on-time up to tMAX_ON, 6.6 µs (typical). With this function, the TPS92200 device maximum duty cycle is able to go up to DMAX, 99% (typical).