JAJSE21B October   2017  – November 2018

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     代表的なアプリケーション回路
  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 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 Undervoltage Lockout (UVLO)
      2. 9.3.2 Power On
      3. 9.3.3 Overvoltage Protection (OVP)
      4. 9.3.4 Dynamic Power-path Management
        1. 9.3.4.1 Input Source Connected (Adapter or USB)
          1. 9.3.4.1.1 Input DPM Mode (VIN-DPM)
          2. 9.3.4.1.2 DPPM Mode
          3. 9.3.4.1.3 Battery Supplement Mode
        2. 9.3.4.2 Input Source Not Connected
      5. 9.3.5 Battery Charging
        1. 9.3.5.1 Charge Current Translator
        2. 9.3.5.2 Battery Detection And Recharge
        3. 9.3.5.3 Battery Disconnect (SYSOFF Input)
        4. 9.3.5.4 Dynamic Charge Timers (TMR Input)
        5. 9.3.5.5 Status Indicators (PGOOD, CHG)
        6. 9.3.5.6 Thermal Regulation And Thermal Shutdown
      6. 9.3.6 Battery Pack Temperature Monitoring
      7. 9.3.7 Half-Wave Adaptors
    4. 9.4 Device Functional Modes
      1. 9.4.1 Sleep Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application – bq24079QW-Q1 Charger Design Example
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Calculations
          1. 10.2.2.1.1 Program the Fast Charge Current (ISET):
          2. 10.2.2.1.2 Program the Input Current Limit (ILIM)
          3. 10.2.2.1.3 Program 6.25-hour Fast-Charge Safety Timer (TMR)
        2. 10.2.2.2 TS Function
        3. 10.2.2.3 CHG and PGOOD
        4. 10.2.2.4 System ON/OFF (SYSOFF)
        5. 10.2.2.5 Selecting In, Out And Bat Pin Capacitors
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 Thermal Package
  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 デベロッパー・ネットワークの製品に関する免責事項
    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

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）
  • RGT|16
サーマルパッド・メカニカル・データ
発注情報

9.3.5.6 Thermal Regulation And Thermal Shutdown

The bq24079QW-Q1 contain a thermal regulation loop that monitors the die temperature. If the temperature exceeds TJ(REG), the device automatically reduces the charging current to prevent the die temperature from increasing further. In some cases, the die temperature continues to rise despite the operation of the thermal loop, particularly under high VIN and heavy OUT system load conditions. Under these conditions, if the die temperature increases to TJ(OFF), the input FET Q1 is turned OFF. FET Q2 is turned ON to ensure that the battery still powers the load on OUT. Once the device die temperature cools by TJ(OFF-HYS), the input FET Q1 is turned on and the device returns to thermal regulation. Continuous overtemperature conditions result in a "hiccup" mode. During thermal regulation, the safety timers are slowed down proportionately to the reduction in current limit.

Note that this feature monitors the die temperature of the bq24079QW-Q1. This is not synonymous with ambient temperature. Self heating exists due to the power dissipated in the IC because of the linear nature of the battery charging algorithm and the LDO associated with OUT. A modified charge cycle with the thermal loop active is shown in Figure 24. Battery termination is disabled during thermal regulation.

bq24079QW-Q1 mod_chg_cyc_lus810.gifFigure 24. Charge Cycle Modified by Thermal Loop