SLUUCJ0 November   2023 BQ76907

 

  1.   1
  2.   Read This First
    1.     About This Manual
    2.     Battery Notational Conventions
    3.     Trademarks
    4.     Glossary
  3. Introduction
  4. Device Description
    1. 2.1 Overview
    2. 2.2 Functional Block Diagram
  5. Device Configuration
    1. 3.1 Direct Commands and Subcommands
    2. 3.2 Configuration Using OTP or Registers
    3. 3.3 Data Formats
      1. 3.3.1 Unsigned Integer
      2. 3.3.2 Integer
      3. 3.3.3 Hex
  6. Device Security
  7. Measurement Subsystem
    1. 5.1 Voltage Measurement
      1. 5.1.1 Voltage Measurement Schedule
      2. 5.1.2 Unused VC Cell Input Pins
      3. 5.1.3 General Purpose ADCIN Functionality
    2. 5.2 Coulomb Counter and Digital Filters
    3. 5.3 Internal Temperature Measurement
    4. 5.4 Thermistor Temperature Measurement
    5. 5.5 Measurement Calibration
  8. Protection Subsystem
    1. 6.1  Protections Overview
    2. 6.2  Protection FET Drivers
    3. 6.3  Cell Overvoltage Protection
    4. 6.4  Cell Undervoltage Protection
    5. 6.5  Short Circuit in Discharge Protection
    6. 6.6  Overcurrent in Charge Protection
    7. 6.7  Overcurrent in Discharge 1 and 2 Protections
    8. 6.8  Current Protection Latch
    9. 6.9  CHG Detector
    10. 6.10 Overtemperature in Charge Protection
    11. 6.11 Overtemperature in Discharge Protection
    12. 6.12 Internal Overtemperature Protection
    13. 6.13 Undertemperature in Charge Protection
    14. 6.14 Undertemperature in Discharge Protection
    15. 6.15 Host Watchdog Protection
    16. 6.16 Cell Open Wire Detection
    17. 6.17 Voltage Reference Measurement Diagnostic Protection
    18. 6.18 VSS Measurement Diagnostic Protection
    19. 6.19 REGOUT Diagnostic Protection
    20. 6.20 LFO Oscillator Integrity Diagnostic Protection
    21. 6.21 Internal Factory Trim Diagnostic Protection
  9. Device Status and Controls
    1. 7.1 0x00 Control Status() and 0x12 Battery Status() Commands
    2. 7.2 LDOs
    3. 7.3 ALERT Pin Operation
    4. 7.4 TS Pin Operation
    5. 7.5 Programmable Timer
    6. 7.6 Device Event Timing
  10. Operational Modes
    1. 8.1 Overview of Operational Modes
    2. 8.2 NORMAL Mode
    3. 8.3 SLEEP Mode
    4. 8.4 DEEPSLEEP Mode
    5. 8.5 SHUTDOWN Mode
    6. 8.6 CONFIG_UPDATE Mode
  11. I2C Serial Communications
    1. 9.1 I2C Serial Communications Interface
  12. 10Cell Balancing
    1. 10.1 Cell Balancing
  13. 11Commands and Subcommands
    1. 11.1 Direct Commands
    2. 11.2 Bit field Definitions for Direct Commands
      1. 11.2.1  Safety Alert A Register
      2. 11.2.2  Safety Status A Register
      3. 11.2.3  Safety Alert B Register
      4. 11.2.4  Safety Status B Register
      5. 11.2.5  Battery Status Register
      6. 11.2.6  Alarm Status Register
      7. 11.2.7  Alarm Raw Status Register
      8. 11.2.8  Alarm Enable Register
      9. 11.2.9  FET CONTROL Register
      10. 11.2.10 REGOUT CONTROL Register
      11. 11.2.11 DSG FET Driver PWM Control Register
      12. 11.2.12 CHG FET Driver PWM Control Register
    3. 11.3 Command-only Subcommands
    4. 11.4 Subcommands with Data
    5. 11.5 Bit field Definitions for Subcommands
      1. 11.5.1 DEVICE NUMBER Register
      2. 11.5.2 FW VERSION Register
      3. 11.5.3 HW VERSION Register
      4. 11.5.4 SECURITY KEYS Register
      5. 11.5.5 CB ACTIVE CELLS Register
      6. 11.5.6 PROG TIMER Register
      7. 11.5.7 PROT RECOVERY Register
  14. 12Data Memory
    1. 12.1 Calibration
      1. 12.1.1 Calibration:Voltage
        1. 12.1.1.1 Calibration:Voltage:Cell 1 Gain
        2. 12.1.1.2 Calibration:Voltage:Cell 2 Gain Delta
        3. 12.1.1.3 Calibration:Voltage:Cell 3 Gain Delta
        4. 12.1.1.4 Calibration:Voltage:Cell 4 and 5 Gain Delta
        5. 12.1.1.5 Calibration:Voltage:Cell 6 and 7 Gain Delta
        6. 12.1.1.6 Calibration:Voltage:Stack Gain
      2. 12.1.2 Calibration:Current
        1. 12.1.2.1 Calibration:Current:Curr Gain
        2. 12.1.2.2 Calibration:Current:Curr Offset
        3. 12.1.2.3 Calibration:Current:CC1 Gain
        4. 12.1.2.4 Calibration:Current:CC1 Offset
      3. 12.1.3 Calibration:Temperature
        1. 12.1.3.1 Calibration:Temperature:TS Offset
        2. 12.1.3.2 Calibration:Temperature:Int Temp Gain
        3. 12.1.3.3 Calibration:Temperature:Int Temp Offset
    2. 12.2 Settings
      1. 12.2.1 Settings:Configuration
        1. 12.2.1.1 Settings:Configuration:Power Config
        2. 12.2.1.2 Settings:Configuration:REGOUT Config
        3. 12.2.1.3 Settings:Configuration:I2C Address
        4. 12.2.1.4 Settings:Configuration:I2C Config
        5. 12.2.1.5 Settings:Configuration:DA Config
        6. 12.2.1.6 Settings:Configuration:Vcell Mode
        7. 12.2.1.7 Settings:Configuration:Default Alarm Mask
        8. 12.2.1.8 Settings:Configuration:FET Options
        9. 12.2.1.9 Settings:Configuration:Charge Detector Time
      2. 12.2.2 Settings:Cell Balancing
        1. 12.2.2.1 Settings:Cell Balancing:Balancing Configuration
        2. 12.2.2.2 Settings:Cell Balancing:Min Temp Threshold
        3. 12.2.2.3 Settings:Cell Balancing:Max Temp Threshold
        4. 12.2.2.4 Settings:Cell Balancing:Max Internal Temp
      3. 12.2.3 Settings:Protection
        1. 12.2.3.1 Settings:Protection:Enabled Protections A
        2. 12.2.3.2 Settings:Protection:Enabled Protections B
        3. 12.2.3.3 Settings:Protection:DSG FET Protections A
        4. 12.2.3.4 Settings:Protection:CHG FET Protections A
        5. 12.2.3.5 Settings:Protection:Both FET Protections B
        6. 12.2.3.6 Settings:Protection:Body Diode Threshold
        7. 12.2.3.7 Settings:Protection:Cell Open Wire NORMAL Check Time
        8. 12.2.3.8 Settings:Protection:Cell Open Wire SLEEP Check Time
        9. 12.2.3.9 Settings:Protection:Host Watchdog Timeout
    3. 12.3 Protections
      1. 12.3.1 Protections:Cell Voltage
        1. 12.3.1.1 Protections:Cell Voltage:Cell Undervoltage Protection Threshold
        2. 12.3.1.2 Protections:Cell Voltage:Cell Undervoltage Protection Delay
        3. 12.3.1.3 Protections:Cell Voltage:Cell Undervoltage Protection Recovery Hysteresis
        4. 12.3.1.4 Protections:Cell Voltage:Cell Overvoltage Protection Threshold
        5. 12.3.1.5 Protections:Cell Voltage:Cell Overvoltage Protection Delay
        6. 12.3.1.6 Protections:Cell Voltage:Cell Overvoltage Protection Recovery Hysteresis
      2. 12.3.2 Protections:Current
        1. 12.3.2.1  Protections:Current:Overcurrent in Charge Protection Threshold
        2. 12.3.2.2  Protections:Current:Overcurrent in Charge Protection Delay
        3. 12.3.2.3  Protections:Current:Overcurrent in Discharge 1 Protection Threshold
        4. 12.3.2.4  Protections:Current:Overcurrent in Discharge 1 Protection Delay
        5. 12.3.2.5  Protections:Current:Overcurrent in Discharge 2 Protection Threshold
        6. 12.3.2.6  Protections:Current:Overcurrent in Discharge 2 Protection Delay
        7. 12.3.2.7  Protections:Current:Short Circuit in Discharge Protection Threshold
        8. 12.3.2.8  Protections:Current:Short Circuit in Discharge Protection Delay
        9. 12.3.2.9  Protections:Current:Latch Limit
        10. 12.3.2.10 Protections:Current:Recovery Time
      3. 12.3.3 Protections:Temperature
        1. 12.3.3.1  Protections:Temperature:Overtemperature in Charge Protection Threshold
        2. 12.3.3.2  Protections:Temperature:Overtemperature in Charge Protection Delay
        3. 12.3.3.3  Protections:Temperature:Overtemperature in Charge Protection Recovery
        4. 12.3.3.4  Protections:Temperature:Undertemperature in Charge Protection Threshold
        5. 12.3.3.5  Protections:Temperature:Undertemperature in Charge Protection Delay
        6. 12.3.3.6  Protections:Temperature:Undertemperature in Charge Protection Recovery
        7. 12.3.3.7  Protections:Temperature:Overtemperature in Discharge Protection Threshold
        8. 12.3.3.8  Protections:Temperature:Overtemperature in Discharge Protection Delay
        9. 12.3.3.9  Protections:Temperature:Overtemperature in Discharge Protection Recovery
        10. 12.3.3.10 Protections:Temperature:Undertemperature in Discharge Protection Threshold
        11. 12.3.3.11 Protections:Temperature:Undertemperature in Discharge Protection Delay
        12. 12.3.3.12 Protections:Temperature:Undertemperature in Discharge Protection Recovery
        13. 12.3.3.13 Protections:Temperature:Internal Overtemperature Protection Threshold
        14. 12.3.3.14 Protections:Temperature:Internal Overtemperature Protection Delay
        15. 12.3.3.15 Protections:Temperature:Internal Overtemperature Protection Recovery
    4. 12.4 Power
      1. 12.4.1 Power:Sleep
        1. 12.4.1.1 Power:Sleep:Sleep Current
        2. 12.4.1.2 Power:Sleep:Voltage Time
        3. 12.4.1.3 Power:Sleep:Wake Comparator Current
      2. 12.4.2 Power:Shutdown
        1. 12.4.2.1 Power:Shutdown:Shutdown Cell Voltage
        2. 12.4.2.2 Power:Shutdown:Shutdown Stack Voltage
        3. 12.4.2.3 Power:Shutdown:Shutdown Temperature
        4. 12.4.2.4 Power:Shutdown:Auto Shutdown Time
    5. 12.5 Security
      1. 12.5.1 Security:Settings
        1. 12.5.1.1 Security:Settings:Security Settings
        2. 12.5.1.2 Security:Settings:Full Access Key Step 1
        3. 12.5.1.3 Security:Settings:Full Access Key Step 2
    6. 12.6 Data Memory Summary
  15. 13Revision History

Voltage Reference Measurement Diagnostic Protection

The BQ76907 device integrates a diagnostic check on the voltage references used by the device. A regular measurement of the internal 1.8 V LDO voltage is included as part of the standard measurement loop in NORMAL and SLEEP modes. As the ADC mux cycles through its periodic measurement loop, it measures this voltage and compares it to the value expected, to implement the Voltage Reference Measurement Diagnostic Protection. Because the ADC uses the VREF1 internal reference, while the internal LDO voltage is based on the VREF2 internal reference, this measurement effectively measures one reference using the other reference. Thus, if one of the two references malfunctions and deviates significantly from its expected value, the resulting measurement result changes and allows detection of this condition. When detected, the device triggers a Voltage Reference Diagnostic Fault and sets 0x03 Safety Status B()[VREF], if enabled, and the device can disable FETs based on settings in Settings:Protection:Both FET Protections B[VREF]. The fault can be recovered by the host sending the 0x009B PROT_RECOVERY()[DIAGREC] subcommand. The expected measurement of the 1.8V LDO in 16-bit codes is 1.8 V / VREF1 × 2 / 5 × 32768 which is approximately 19228. The diagnostic protection alert is triggered whenever the measured result is below 14592 or above 24320. The diagnostic protection status fault is triggered when this occurs for two consecutive measurements.