JAJSGI6C September   2011  – January 2020 BQ24725A

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  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 Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 SMBus Interface
    4. 8.4 Device Functional Modes
      1. 8.4.1  Adapter Detect and ACOK Output
      2. 8.4.2  Adapter Over Voltage (ACOVP)
      3. 8.4.3  System Power Selection
      4. 8.4.4  Battery LEARN Cycle
      5. 8.4.5  Enable and Disable Charging
      6. 8.4.6  Automatic Internal Soft-Start Charger Current
      7. 8.4.7  High Accuracy Current Sense Amplifier
      8. 8.4.8  Charge Timeout
      9. 8.4.9  Converter Operation
      10. 8.4.10 Continuous Conduction Mode (CCM)
      11. 8.4.11 Discontinuous Conduction Mode (DCM)
      12. 8.4.12 Input Over Current Protection (ACOC)
      13. 8.4.13 Charge Over Current Protection (CHGOCP)
      14. 8.4.14 Battery Over Voltage Protection (BATOVP)
      15. 8.4.15 Battery Shorted to Ground (BATLOWV)
      16. 8.4.16 Thermal Shutdown Protection (TSHUT)
      17. 8.4.17 EMI Switching Frequency Adjust
      18. 8.4.18 Inductor Short, MOSFET Short Protection
    5. 8.5 Register Maps
      1. 8.5.1 Battery-Charger Commands
      2. 8.5.2 Setting Charger Options
        1. Table 3. Charge Options Register (0x12H)
      3. 8.5.3 Setting the Charge Current
        1. Table 4. Charge Current Register (0x14H), Using 10mΩ Sense Resistor
      4. 8.5.4 Setting the Charge Voltage
        1. Table 5. Charge Voltage Register (0x15H)
      5. 8.5.5 Setting Input Current
        1. Table 6. Input Current Register (0x3FH), Using 10mΩ Sense Resistor
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical System with Two NMOS Selector
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Negative Output Voltage Protection
          2. 9.2.1.2.2 Reverse Input Voltage Protection
          3. 9.2.1.2.3 Reduce Battery Quiescent Current
          4. 9.2.1.2.4 Inductor Selection
          5. 9.2.1.2.5 Input Capacitor
          6. 9.2.1.2.6 Output Capacitor
          7. 9.2.1.2.7 Power MOSFETs Selection
          8. 9.2.1.2.8 Input Filter Design
          9. 9.2.1.2.9 BQ24725A Design Guideline
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Simplified System without Power Path
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
    3. 9.3 System Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 12.2 ドキュメントの更新通知を受け取る方法
    3. 12.3 サポート・リソース
    4. 12.4 商標
    5. 12.5 静電気放電に関する注意事項
    6. 12.6 Glossary
  13. 13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

9.2.1.2.3 Reduce Battery Quiescent Current

When the adapter is not present, if VCC is powered with voltage higher than UVLO directly or indirectly (such as through a LDO or switching converter) from battery, the internal BATFET charge pump gives the BATFET pin 6V higher voltage than the SRN pin to drive the n-channel BATFET. As a result, the battery has higher quiescent current. This is only necessary when the battery powers the system due to a high system current that goes through the MOSFET channel instead of the body diode to reduce conduction loss and extend the battery working life. When the system is totally shutdown, it is not necessary to let the internal BATFET charge pump work. The host controller can use a digital signal EN to disconnect the battery power path to the VCC pin by U2 in Figure 18. As a result, battery quiescent current can be minimized. The host controller still can get power from BATFET body diode because the total system current is the lowest when the system is shutdown, so there is no high conduction loss of the body diode.