JAJSVO8 November   2024 TPS922051

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Adaptive Off-Time Current Mode Control
      2. 7.3.2 Setting LED Current
      3. 7.3.3 Internal Soft Start
      4. 7.3.4 Dimming Mode
        1. 7.3.4.1 PWM Dimming
        2. 7.3.4.2 Analog Dimming
      5. 7.3.5 Fault Protection
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 TPS922051D2 24V Input, 2A Output, 4-piece WLED 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
          4. 8.2.1.2.4 Sense Resistor Selection
          5. 8.2.1.2.5 Other External Components Selection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 TPS922050D1 48V Input, 1A Output, 12-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
          4. 8.2.2.2.4 Sense Resistor Selection
          5. 8.2.2.2.5 Other External Components Selection
        3. 8.2.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 ドキュメントの更新通知を受け取る方法
    2. 9.2 サポート・リソース
    3. 9.3 Trademarks
    4. 9.4 静電気放電に関する注意事項
    5. 9.5 用語集
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Package Option Addendum
    2. 11.2 Tape and Reel Information

7.3.4.2 Analog Dimming

The TPS922050D2 and TPS922051D2 support analog dimming which regulates the LED current through the analog input signal at the DIM pin.

The internal voltage reference, VREF, starts to rise after the device exit UVLO. Once an analog voltage appears at the DIM pin, VREF continues to increase until changing to the desired value in proportion to the analog voltage.

VREF is 200mV when the analog input signal at the DIM pin is 2V, for instance, and VREF is 20mV when the analog input signal is 0.2V. VREF is clamped at 220mV when the analog input signal at the DIM pin is higher than 2.2V. VREF is 0V and the device stops switching when the analog input signal is lower than 10mV. The circuit is able to respond to the voltage change of the analog input signal with micro-seconds delay.