SLUSBV4B June   2018  – September 2020 BQ40Z80

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Primary (1st Level) Safety Features
      2. 8.3.2  Secondary (2nd Level) Safety Features
      3. 8.3.3  Charge Control Features
      4. 8.3.4  Gas Gauging
      5. 8.3.5  Multifunction Pins
      6. 8.3.6  Configuration
        1. 8.3.6.1 Oscillator Function
        2. 8.3.6.2 System Present Operation
        3. 8.3.6.3 Emergency Shutdown
        4. 8.3.6.4 2-Series, 3-Series, 4-Series, 5-Series, or 6-Series Cell Configuration
        5. 8.3.6.5 Cell Balancing
      7. 8.3.7  Battery Parameter Measurements
        1. 8.3.7.1 Charge and Discharge Counting
      8. 8.3.8  Lifetime Data Logging Features
      9. 8.3.9  Authentication
      10. 8.3.10 LED Display
      11. 8.3.11 IATA Support
      12. 8.3.12 Voltage
      13. 8.3.13 Current
      14. 8.3.14 Temperature
      15. 8.3.15 Communications
        1. 8.3.15.1 SMBus On and Off State
        2. 8.3.15.2 SBS Commands
    4. 8.4 Device Functional Modes
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Using the BQ40Z80EVM with BQSTUDIO
        2. 9.2.2.2 High-Current Path
          1. 9.2.2.2.1 Protection FETs
          2. 9.2.2.2.2 Chemical Fuse
          3. 9.2.2.2.3 Lithium-Ion Cell Connections
          4. 9.2.2.2.4 Sense Resistor
          5. 9.2.2.2.5 ESD Mitigation
        3. 9.2.2.3 Gas Gauge Circuit
          1. 9.2.2.3.1 Coulomb-Counting Interface
          2. 9.2.2.3.2 Power Supply Decoupling and PBI
          3. 9.2.2.3.3 System Present
          4. 9.2.2.3.4 SMBus Communication
          5. 9.2.2.3.5 FUSE Circuitry
        4. 9.2.2.4 Secondary-Current Protection
          1. 9.2.2.4.1 Cell and Battery Inputs
          2. 9.2.2.4.2 External Cell Balancing
          3. 9.2.2.4.3 PACK and FET Control
          4. 9.2.2.4.4 Pre-Discharge Control
          5. 9.2.2.4.5 Temperature Output
          6. 9.2.2.4.6 LEDs
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Protector FET Bypass and Pack Terminal Bypass Capacitors
      2. 11.1.2 ESD Spark Gap
    2. 11.2 Layout Examples
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.6.5 Cell Balancing

For up to a 6-series cell configuration, the device supports cell balancing by bypassing the current of each cell during charging or at rest. If the device's internal bypass is used, up to 10 mA can be bypassed and multiple cells can be bypassed at the same time. A higher cell balance current can be achieved by using an external cell balancing circuit. In EXTERNAL CELL BALANCING mode, only one cell at a time can be balanced.

The cell balancing algorithm determines the amount of charge needed to be bypassed to balance the capacity of all cells.