JAJSSA8 November   2023 BQ76905

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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  Supply Current
    6. 6.6  Digital I/O
    7. 6.7  REGOUT LDO
    8. 6.8  Voltage References
    9. 6.9  Coulomb Counter
    10. 6.10 Coulomb Counter Digital Filter
    11. 6.11 Current Wake Detector
    12. 6.12 Analog-to-Digital Converter
    13. 6.13 Cell Balancing
    14. 6.14 Internal Temperature Sensor
    15. 6.15 Thermistor Measurement
    16. 6.16 Hardware Overtemperature Detector
    17. 6.17 Internal Oscillator
    18. 6.18 Charge and Discharge FET Drivers
    19. 6.19 Comparator-Based Protection Subsystem
    20. 6.20 Timing Requirements—I2C Interface, 100-kHz Mode
    21. 6.21 Timing Requirements—I2C Interface, 400-kHz Mode
    22. 6.22 Timing Diagram
    23. 6.23 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Device Configuration
      1. 7.3.1 Commands and Subcommands
      2. 7.3.2 Configuration Using OTP or Registers
      3. 7.3.3 Device Security
    4. 7.4 Device Hardware Features
      1. 7.4.1  Voltage ADC
      2. 7.4.2  Coulomb Counter and Digital Filters
      3. 7.4.3  Protection FET Drivers
      4. 7.4.4  Voltage References
      5. 7.4.5  Multiplexer
      6. 7.4.6  LDOs
      7. 7.4.7  Standalone Versus Host Interface
      8. 7.4.8  ALERT Pin Operation
      9. 7.4.9  Low Frequency Oscillator
      10. 7.4.10 I2C Serial Communications Interface
    5. 7.5 Measurement Subsystem
      1. 7.5.1 Voltage Measurement
        1. 7.5.1.1 Voltage ADC Scheduling
        2. 7.5.1.2 Unused VC Pins
        3. 7.5.1.3 General Purpose ADCIN Functionality
      2. 7.5.2 Current Measurement and Charge Integration
      3. 7.5.3 Internal Temperature Measurement
      4. 7.5.4 Thermistor Temperature Measurement
      5. 7.5.5 Factory Trim and Calibration
    6. 7.6 Protection Subsystem
      1. 7.6.1 Protections Overview
      2. 7.6.2 Primary Protections
      3. 7.6.3 CHG Detector
      4. 7.6.4 Cell Open-Wire Protection
      5. 7.6.5 Diagnostic Checks
    7. 7.7 Cell Balancing
    8. 7.8 Device Operational Modes
      1. 7.8.1 Overview of Operational Modes
      2. 7.8.2 NORMAL Mode
      3. 7.8.3 SLEEP Mode
      4. 7.8.4 DEEPSLEEP Mode
      5. 7.8.5 SHUTDOWN Mode
      6. 7.8.6 CONFIG_UPDATE Mode
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Performance Plot
      4. 8.2.4 Random Cell Connection Support
      5. 8.2.5 Startup Timing
      6. 8.2.6 FET Driver Turn-Off
      7. 8.2.7 Usage of Unused Pins
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 ドキュメントの更新通知を受け取る方法
    3. 9.3 サポート・リソース
    4. 9.4 Trademarks
    5. 9.5 静電気放電に関する注意事項
    6. 9.6 用語集
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

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

7.5.1.2 Unused VC Pins

If the BQ76905 device is used in a system with fewer than 5 series cells, specific cells must be used for connection to real cells, as shown in Table 7-1. The unused cell inputs should be shorted out on the circuit board. The device only measures and reports data for those cells designated as real cells.

Table 7-1 Cell Usage
NUMBER OF CELL USEDCELL CONNECTIONSSHORTED CONNECTIONS
5VC5‒VC4A, VC4B‒VC3A, VC3B‒VC2, VC2‒VC1, VC1‒VC0VC4A‒VC4B, VC3A‒VC3B
4VC5‒VC4A, VC4B‒VC3A, VC2‒VC1, VC1‒VC0VC4A‒VC4B, VC3A‒VC3B, VC3B‒VC2
3VC5‒VC4A, VC2‒VC1, VC1‒VC0VC4A‒VC4B, VC4B‒VC3A, VC3A‒VC3B, VC3B‒VC2
2VC5‒VC4A, VC1‒VC0VC4A‒VC4B, VC4B‒VC3A, VC3A‒VC3B, VC3B‒VC2, VC2‒VC1

The unused cell input pins should be shorted to adjacent cell input pins, as shown in Figure 8-12 for a 4-s configuration.

It is also important to note that the range of voltages supported by the different VC pins differs depending on the pin. For example, pins VC4A, VC4B, and VC5 can only support measurements if their pin voltage is greater than or equal to 2 V. Thus, if implementing a 2-s system using the top and bottom cell input pins, the upper cell voltage may not be measured correctly if the lower cell voltage drops below 2 V, since then VC4A would be below 2 V.


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Figure 7-5 Connecting an Unused Cell Input Pin

The device data memory must be configured to specify which cell inputs are used for actual cells. The device uses this information to disable cell voltage protections associated with inputs which are not used. Voltage measurements for inputs used for real cells are reported in 16-bit format (in units of mV). See the BQ76905 Technical Reference Manual for further details.