JAJST23 June   2024 BQ41Z50

ADVANCE INFORMATION  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 概要 (続き)
  6. 5 Pin Configuration and Functions
    1. 5.1 Pin Equivalent Diagrams
  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  Power Supply Control
    7. 6.7  Current Wake Detector
    8. 6.8  VC0, VC1, VC2, VC3, VC4, PACK
    9. 6.9  SMBD, SMBC
    10. 6.10 PRES/SHUTDN, DISP
    11. 6.11 ALERT
    12. 6.12 Coulomb Counter Digital Filter (CC1)
    13. 6.13 ADC Digital Filter
    14. 6.14 CHG, DSG High-side NFET Drivers
    15. 6.15 Precharge (PCHG) FET Drive
    16. 6.16 FUSE Drive
    17. 6.17 Internal Temperature Sensor
    18. 6.18 TS1, TS2, TS3, TS4
    19. 6.19 Flash Memory
    20. 6.20 GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO6, GPIO7
    21. 6.21 Elliptical Curve Cryptography (ECC)
    22. 6.22 SMBus Interface Timing
    23. 6.23 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Primary (1st Level) Safety Features
      2. 7.3.2 Secondary (2nd Level) Safety Features
      3. 7.3.3 Charge Control Features
      4. 7.3.4 Gas Gauging
      5. 7.3.5 Lifetime Data Logging Features
      6. 7.3.6 Authentication
      7. 7.3.7 Configuration
        1. 7.3.7.1 Oscillator Function
        2. 7.3.7.2 Real Time Clock
        3. 7.3.7.3 System Present Operation
        4. 7.3.7.4 Emergency Shutdown
        5. 7.3.7.5 2-Series, 3-Series, or 4-Series Cell Configuration
        6. 7.3.7.6 Cell Balancing
        7. 7.3.7.7 LED Display
      8. 7.3.8 Battery Parameter Measurements
        1. 7.3.8.1 Charge and Discharge Counting
        2. 7.3.8.2 Voltage
        3. 7.3.8.3 Current
        4. 7.3.8.4 Temperature
        5. 7.3.8.5 Communications
          1. 7.3.8.5.1 SMBus On and Off State
    4. 7.4 Device Functional Modes
  9. 8 Applications 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 High-Current Path
          1. 8.2.2.1.1 Protection FETs
          2. 8.2.2.1.2 Chemical Fuse
          3. 8.2.2.1.3 Lithium-Ion Cell Connections
          4. 8.2.2.1.4 Sense Resistor
          5. 8.2.2.1.5 ESD Mitigation
        2. 8.2.2.2 Gas Gauge Circuit
          1. 8.2.2.2.1 Coulomb-Counting Interface
          2. 8.2.2.2.2 Low-dropout Regulators (LDOs)
            1. 8.2.2.2.2.1 REG18
            2. 8.2.2.2.2.2 REG135
          3. 8.2.2.2.3 System Present
          4. 8.2.2.2.4 SMBus Communication
          5. 8.2.2.2.5 FUSE Circuitry
        3. 8.2.2.3 Secondary-Current Protection
          1. 8.2.2.3.1 Cell and Battery Inputs
          2. 8.2.2.3.2 External Cell Balancing
          3. 8.2.2.3.3 PACK and FET Control
          4. 8.2.2.3.4 Temperature Measurement
          5. 8.2.2.3.5 LEDs
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Protector FET Bypass and Pack Terminal Bypass Capacitors
        2. 8.4.1.2 ESD Spark Gap
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 サード・パーティ製品に関する免責事項
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 サポート・リソース
    5. 9.5 Trademarks
    6. 9.6 静電気放電に関する注意事項
    7. 9.7 用語集
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
8.2.2.1.3 Lithium-Ion Cell Connections

The important part to remember about the cell connections is that high current flows through the top and bottom connections; therefore, the voltage sense leads at these points must be made with a Kelvin connection to avoid any errors due to a drop in the high-current copper trace. The location marked 4P in Figure 8-4 indicates the Kelvin connection of the most positive battery node. The single-point connection at 1N to the low-current ground is needed to avoid an undesired voltage drop through long traces while the gas gauge is measuring the bottom cell voltage.

BQ41Z50 Lithium-Ion Cell Connections Figure 8-4 Lithium-Ion Cell Connections