SLUSET3 December   2022 BQ28Z620

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (continued)
  6. BQ28Z620 Changes from BQ28Z610-R1
  7. Pin Configuration and Functions
  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  Supply Current
    6. 8.6  Power Supply Control
    7. 8.7  Power-On Reset (POR)
    8. 8.8  Internal 1.8-V LDO
    9. 8.9  Current Wake Comparator
    10. 8.10 Coulomb Counter
    11. 8.11 ADC Digital Filter
    12. 8.12 ADC Multiplexer
    13. 8.13 Cell Balancing Support
    14. 8.14 Internal Temperature Sensor
    15. 8.15 NTC Thermistor Measurement Support
    16. 8.16 High-Frequency Oscillator
    17. 8.17 Low-Frequency Oscillator
    18. 8.18 Voltage Reference 1
    19. 8.19 Voltage Reference 2
    20. 8.20 Instruction Flash
    21. 8.21 Data Flash
    22. 8.22 Current Protection Thresholds
    23. 8.23 Current Protection Timing
    24. 8.24 N-CH FET Drive (CHG, DSG)
    25. 8.25 I2C Interface I/O
    26. 8.26 I2C Interface Timing
    27. 8.27 Typical Characteristics
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Battery Parameter Measurements
        1. 9.3.1.1 BQ28Z620 Processor
      2. 9.3.2  Coulomb Counter (CC)
      3. 9.3.3  CC Digital Filter
      4. 9.3.4  ADC Multiplexer
      5. 9.3.5  Analog-to-Digital Converter (ADC)
      6. 9.3.6  ADC Digital Filter
      7. 9.3.7  Internal Temperature Sensor
      8. 9.3.8  External Temperature Sensor Support
      9. 9.3.9  Power Supply Control
      10. 9.3.10 Power-On Reset
      11. 9.3.11 Bus Communication Interface
      12. 9.3.12 I2C Timeout
      13. 9.3.13 Cell Balancing Support
      14. 9.3.14 N-Channel Protection FET Drive
      15. 9.3.15 Low Frequency Oscillator
      16. 9.3.16 High Frequency Oscillator
      17. 9.3.17 1.8-V Low Dropout Regulator
      18. 9.3.18 Internal Voltage References
      19. 9.3.19 Overcurrent in Discharge Protection
      20. 9.3.20 Short-Circuit Current in Charge Protection
      21. 9.3.21 Short-Circuit Current in Discharge 1 and 2 Protection
      22. 9.3.22 Primary Protection Features
      23. 9.3.23 Gas Gauging
      24. 9.3.24 Charge Control Features
      25. 9.3.25 Authentication
    4. 9.4 Device Functional Modes
      1. 9.4.1 Lifetime Logging Features
      2. 9.4.2 Configuration
        1. 9.4.2.1 Coulomb Counting
        2. 9.4.2.2 Cell Voltage Measurements
        3. 9.4.2.3 Current Measurements
        4. 9.4.2.4 Auto Calibration
        5. 9.4.2.5 Temperature Measurements
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Design Requirements (Default)
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Setting Design Parameters
        2. 10.2.2.2 Calibration Process
        3. 10.2.2.3 Gauging Data Updates
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

Setting Design Parameters

For the firmware settings needed for the design requirements, refer to the BQ28Z620 Technical Reference Manual.

  • To set the 2s1p battery pack, go to data flash Configuration: DA Configuration register's bit 0 (CC0) = 1.
  • To set design capacity, set the data flash value to 4400 in the Gas Gauging: Design: Design Capacity register.
  • To set device chemistry, go to data flash SBS Configuration: Data: Device Chemistry. The BQStudio software automatically populates the correct chemistry identification. This selection is derived from using the BQChem feature in the tools and choosing the option that matches the device chemistry from the list.
  • To protect against cell overvoltage, set the data flash value to 4300 in Protections: COV: Standard Temp.
  • To protect against cell undervoltage, set the data flash value to 2500 in the Protections: CUV register.
  • To set the shutdown voltage to prevent further pack depletion due to low pack voltage, program Power: Shutdown: Shutdown voltage = 2300.
  • To protect against large charging currents when the AC adapter is attached, set the data flash value to 6000 in the Protections: OCC: Threshold register.
  • To protect against large discharging currents when heavy loads are attached, set the data flash value to –6000 in the Protections: OCD: Threshold register.
  • Program a short circuit delay timer and threshold setting to enable the operating the system for large short transient current pulses. These two parameters are under Protections: ASCC: Threshold = 100 for charging current. The discharge current setting is Protections: ASCD:Threshold = –100 mV.
  • To prevent the cells from overcharging and adding a second level of safety, there is a register setting that will shut down the device if any of the cells voltage measurement is greater than the Safety Over Voltage setting for greater than the delay time. Set this data flash value to 4500 in Permanent Fail: SOV: Threshold.
  • To disable the cell balancing feature, set the data flash value to 0 in Settings: Configuration: Balancing Configuration: bit 0 (CB).
  • To enable the internal temperature and the external temperature sensors: Set Settings:Configuration: Temperature Enable: Bit 0 (TSInt) = 1 for the internal sensor; set Bit 1 (TS1) = 1 for the external sensor.
  • To prevent charging of the battery pack if the temperature falls below 0°C, set Protections: UTC:Threshold = 0.
  • To prevent discharging of the battery pack if the temperature falls below 0°C, set Protections: UTD:Threshold = 0.
  • To provide required information to the smart chargers, the gas gauge must operate in BROADCAST mode. To enable this, set the [BCAST] bit in Configuration: SBS Configuration 2: Bit 0 [BCAST] = 1.

Each parameter listed for fault trigger thresholds has a delay timer setting associated for any noise filtering. These values, along with the trigger thresholds for fault detection, may be changed based upon the application requirements using the data flash settings in the appropriate register stated in the BQ28Z620 Technical Reference Manual.