SLUSE97 November   2023 BQ76905

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.1 Design Requirements

Table 8-1 BQ76905 Design Requirements
DESIGN PARAMETER EXAMPLE VALUE
Minimum system operating voltage 12.5 V
Cell minimum operating voltage 2.5 V
Series cell count 5
Sense resistor 1 mΩ
Thermistor in use yes
Charge voltage 21.25 V
Maximum charge current 6.0 A
Peak discharge current 40.0 A
Configuration settings programmed in registers during customer production
Measurement speed Set to highest resolution (2.93 ms per measurement)
Protection subsystem configuration Series FET configuration, device monitors, disables FETs upon fault, recovers autonomously
OV protection threshold 4.30 V
OV protection delay 369 ms (21 ADSCAN cycles)
OV protection recovery hysteresis 100 mV
UV protection threshold 2.5 V
UV protection delay 141 ms (8 ADSCAN cycles)
UV protection recovery hysteresis 100 mV
SCD protection threshold 80 mV (corresponding to a nominal 80 A, based on a 1-mΩ sense resistor)
SCD protection delay 45 ~ 60 µs
OCD1 protection threshold 68 mV (corresponding to a nominal 68 A, based on a 1-mΩ sense resistor)
OCD1 protection delay 10 ms
OCD2 protection threshold 56 mV (corresponding to a nominal 56 A, based on a 1-mΩ sense resistor)
OCD2 protection delay 81 ms
OCC protection threshold 8 mV (corresponding to a nominal 8 A, based on a 1-mΩ sense resistor)
OCC protection delay 159 ms
OTD protection threshold Code = 2592 (corresponding to ~ 60°C)
OTD protection delay 2 seconds (23 FULLSCANs)
OTD protection recovery Code = 2970 (corresponding to ~ 55°C) for 2 seconds
OTC protection threshold Code = 3888 (corresponding to ~ 45°C)
OTC protection delay 2 seconds (23 FULLSCANs)
OTC protection recovery Code = 4428 (corresponding to ~ 40°C) for 2 seconds
UTD protection threshold Code = 15169 (corresponding to ~ –20°C)
UTD protection delay 8 seconds (91 FULLSCANs)
UTD protection recovery Code = 13398 (corresponding to ~ –10°C) for 2 seconds
UTC protection threshold Code = 11319 (corresponding to ~ 0°C)
UTC protection delay 5 seconds (57 FULLSCANs)
UTC protection recovery Code = 10318 (corresponding to ~ 5°C) for 2 seconds
Host watchdog timeout protection delay 5 seconds
ALERT pin functionality Used for alarm interrupt function
REGOUT LDO Usage Enabled with 3.3-V output