JAJSH28D November   2013  – March 2019 LM3697

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      昇圧効率
  4. 4 改訂履歴
  5. 5 Pin Configuration and Functions
    1.     Pin 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. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 PWM Input
      2. 7.1.2 HWEN Input
      3. 7.1.3 Thermal Shutdown
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Descriptions
      1. 7.3.1 High-Voltage LED Control
        1. 7.3.1.1 High-Voltage Boost Converter
        2. 7.3.1.2 High-Voltage Current Sinks (HVLED1, HVLED2 and HVLED3)
        3. 7.3.1.3 High-Voltage Current String Biasing
      2. 7.3.2 Boost Switching-Frequency Select
      3. 7.3.3 Automatic Switching Frequency Shift
      4. 7.3.4 Brightness Register Current Control
        1. 7.3.4.1 8-Bit Control (Preferred)
        2. 7.3.4.2 11-Bit Control
      5. 7.3.5 PWM Control
        1. 7.3.5.1 PWM Input Frequency Range
        2. 7.3.5.2 PWM Input Polarity
        3. 7.3.5.3 PWM Zero Detection
      6. 7.3.6 Start-up/Shutdown Ramp
      7. 7.3.7 Run-Time Ramp
      8. 7.3.8 High-Voltage Control A and B Ramp Select
    4. 7.4 Device Functional Modes
      1. 7.4.1 LED Current Mapping Modes
        1. 7.4.1.1 Exponential Mapping
          1. 7.4.1.1.1 8-Bit Code Calculation
          2. 7.4.1.1.2 11-Bit Code Calculation
        2. 7.4.1.2 Linear Mapping
          1. 7.4.1.2.1 8-Bit Code Calculation
          2. 7.4.1.2.2 11-Bit Code Calculation
      2. 7.4.2 Fault Flags/Protection Features
        1. 7.4.2.1 Open LED String (HVLED)
        2. 7.4.2.2 Shorted LED String (HVLED)
        3. 7.4.2.3 Overvoltage Protection (Inductive Boost)
        4. 7.4.2.4 Current Limit (Inductive Boost)
      3. 7.4.3 I2C-Compatible Interface
        1. 7.4.3.1 Start And Stop Conditions
        2. 7.4.3.2 I2C-Compatible Address
        3. 7.4.3.3 Transferring Data
        4. 7.4.3.4 High-Speed Mode
    5. 7.5 Register Maps
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Boost Converter Maximum Output Power
          1. 8.2.2.1.1 Peak Current Limited
          2. 8.2.2.1.2 Output Voltage Limited
        2. 8.2.2.2 Inductor Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Schottky Diode Selection
        5. 8.2.2.5 Input Capacitor Selection
        6. 8.2.2.6 Application Circuit Component List
      3. 8.2.3 Application Performance Plots
    3. 8.3 Initialization Set Up
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Boost Output Capacitor Placement
      2. 10.1.2 Schottky Diode Placement
      3. 10.1.3 Inductor Placement
      4. 10.1.4 Boost Input Capacitor Placement
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 11.2 関連資料
    3. 11.3 ドキュメントの更新通知を受け取る方法
    4. 11.4 コミュニティ・リソース
    5. 11.5 商標
    6. 11.6 静電気放電に関する注意事項
    7. 11.7 Glossary
  12. 12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

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • YFQ|12
サーマルパッド・メカニカル・データ
発注情報

8.2.2.1.2 Output Voltage Limited

In the case of an output voltage limited situation (VOUT = VOVP), when the boost output voltage hits the LM3697 device's OVP threshold, the NFET turns off and stays off until the output voltage falls below the hysteresis level (typically 1 V below the OVP threshold). This results in the boost converter regulating the output voltage to the programmed OVP threshold (16 V, 24 V, 32 V, or 40 V), causing the current sinks to go into dropout. The default OVP threshold is set at 16 V. For LED strings higher than typically 4 series LEDs, the OVP has to be programmed higher after power-up, Software Reset, or HWEN reset.