JAJSHN1A June   2019  – August 2019 LP8867-Q1 , LP8869-Q1

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     概略回路図
    2.     LED バックライトの効率
  4. 4 改訂履歴
  5. 5 概要 (続き)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1  Absolute Maximum Ratings
    2. 8.2  ESD Ratings
    3. 8.3  Recommended Operating Conditions
    4. 8.4  Thermal Information
    5. 8.5  Electrical Characteristics
    6. 8.6  Internal LDO Electrical Characteristics
    7. 8.7  Protection Electrical Characteristics
    8. 8.8  Current Sinks Electrical Characteristics
    9. 8.9  PWM Brightness Control Electrical Characteristics
    10. 8.10 Boost and SEPIC Converter Characteristics
    11. 8.11 Logic Interface Characteristics
    12. 8.12 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Integrated DC-DC Converter
        1. 9.3.1.1 DC-DC Converter Parameter Configuration
          1. 9.3.1.1.1 Switching Frequency
          2. 9.3.1.1.2 Spread Spectrum and External SYNC
          3. 9.3.1.1.3 Recommended Component Value and Internal Parameters
          4. 9.3.1.1.4 DC-DC Converter Switching Current Limit
          5. 9.3.1.1.5 DC-DC Converter Light Load Mode
        2. 9.3.1.2 Adaptive Voltage Control
          1. 9.3.1.2.1 Using Two-Divider
          2. 9.3.1.2.2 Using T-Divider
          3. 9.3.1.2.3 Feedback Capacitor
      2. 9.3.2 Internal LDO
      3. 9.3.3 LED Current Sinks
        1. 9.3.3.1 LED Output Configuration
        2. 9.3.3.2 LED Current Setting
        3. 9.3.3.3 Brightness Control
      4. 9.3.4 Power-Line FET Control
      5. 9.3.5 LED Current Dimming With External Temperature Sensor
      6. 9.3.6 Fault Detections and Protection
        1. 9.3.6.1 Supply Fault and Protection
          1. 9.3.6.1.1 VIN Undervoltage Fault (VIN_UVLO)
          2. 9.3.6.1.2 VIN Overvoltage Fault (VIN_OVP)
          3. 9.3.6.1.3 VIN Overcurrent Fault (VIN_OCP)
        2. 9.3.6.2 Boost Fault and Protection
          1. 9.3.6.2.1 Boost Overvoltage Fault (BST_OVP)
          2. 9.3.6.2.2 SW Overvoltage Fault (SW_OVP)
        3. 9.3.6.3 LED Fault and Protection (LED_OPEN and LED_SHORT)
        4. 9.3.6.4 Thermal Fault and Protection (TSD)
        5. 9.3.6.5 Overview of the Fault and Protection Schemes
    4. 9.4 Device Functional Modes
      1. 9.4.1 STANDBY State
      2. 9.4.2 SOFT START State
      3. 9.4.3 BOOST START State
      4. 9.4.4 NORMAL State
      5. 9.4.5 FAULT RECOVERY State
      6. 9.4.6 State Diagram and Timing Diagram for Start-up and Shutdown
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Typical Application for 4 LED Strings
      2. 10.2.2 Design Requirements
      3. 10.2.3 Detailed Design Procedure
        1. 10.2.3.1 Inductor Selection
        2. 10.2.3.2 Output Capacitor Selection
        3. 10.2.3.3 Input Capacitor Selection
        4. 10.2.3.4 LDO Output Capacitor
        5. 10.2.3.5 Diode
      4. 10.2.4 Application Curves
      5. 10.2.5 SEPIC Mode Application
        1. 10.2.5.1 Design Requirements
        2. 10.2.5.2 Detailed Design Procedure
          1. 10.2.5.2.1 Inductor
          2. 10.2.5.2.2 Diode
          3. 10.2.5.2.3 Capacitor C1
        3. 10.2.5.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 デバイス・サポート
      1. 13.1.1 開発サポート
    2. 13.2 ドキュメントのサポート
      1. 13.2.1 関連資料
    3. 13.3 ドキュメントの更新通知を受け取る方法
    4. 13.4 コミュニティ・リソース
    5. 13.5 商標
    6. 13.6 静電気放電に関する注意事項
    7. 13.7 Glossary
  14. 14メカニカル、パッケージ、および注文情報

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

10.2.5 SEPIC Mode Application

When LED string voltage can be above or below VIN voltage, SEPIC configuration can be used. In this example, two separate coils or coupled coil could both be used for SEPIC. Separate coils can enable lower height external components to be used, compared to a coupled coil solution. On the other hand, coupled coil typically maximizes the efficiency. Also, in this example, an external clock is used to synchronize SEPIC switching frequency. External clock input can be modulated to spread switching frequency spectrum.

LP8867-Q1 LP8869-Q1 fb-08-APP2-SEPIC.gifFigure 25. SEPIC Mode, 4 Strings 100-mA per String Configuration