JAJSUU2B October   2014  – June 2024 TPS61169

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 Soft Start-Up
      2. 6.3.2 Open LED Protection
      3. 6.3.3 Shutdown
      4. 6.3.4 Current Program
      5. 6.3.5 LED Brightness Dimming
      6. 6.3.6 Undervoltage Lockout
      7. 6.3.7 Thermal Foldback and Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Operation With CTRL
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Inductor Selection
        2. 7.2.2.2 Schottky Diode Selection
        3. 7.2.2.3 Output Capacitor Selection
        4. 7.2.2.4 LED Current Set Resistor
        5. 7.2.2.5 Thermal Considerations
    3. 7.3 Application Curves
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
    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

6.3.4 Current Program

The FB voltage is regulated by a low 204mV reference voltage. The LED current is programmed externally using a current-sense resistor in series with the LED string(s). The value of the RSET is calculated using:

Equation 1. TPS61169

where

  • ILED = total output current of LED string(s)
  • VFB = regulated voltage of FB pin
  • RSET = current sense resistor

The output current tolerance depends on the FB accuracy and the current sensor resistor accuracy.