SLUSE14B December   2020  – December 2021 BQ76942

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 BQ76942
    5. 7.5  Supply Current
    6. 7.6  Digital I/O
    7. 7.7  LD Pin
    8. 7.8  Precharge (PCHG) and Predischarge (PDSG) FET Drive
    9. 7.9  FUSE Pin Functionality
    10. 7.10 REG18 LDO
    11. 7.11 REG0 Pre-regulator
    12. 7.12 REG1 LDO
    13. 7.13 REG2 LDO
    14. 7.14 Voltage References
    15. 7.15 Coulomb Counter
    16. 7.16 Coulomb Counter Digital Filter (CC1)
    17. 7.17 Current Measurement Digital Filter (CC2)
    18. 7.18 Current Wake Detector
    19. 7.19 Analog-to-Digital Converter
    20. 7.20 Cell Balancing
    21. 7.21 Cell Open Wire Detector
    22. 7.22 Internal Temperature Sensor
    23. 7.23 Thermistor Measurement
    24. 7.24 Internal Oscillators
    25. 7.25 High-Side NFET Drivers
    26. 7.26 Comparator-Based Protection Subsystem
    27. 7.27 Timing Requirements – I2C Interface, 100kHz Mode
    28. 7.28 Timing Requirements – I2C Interface, 400kHz Mode
    29. 7.29 Timing Requirements – HDQ Interface
    30. 7.30 Timing Requirements – SPI Interface
    31. 7.31 Interface Timing Diagrams
    32. 7.32 Typical Characteristics
  8. 8 Device Description
    1. 8.1 Overview
    2. 8.2 BQ76942 Device Versions
    3. 8.3 Functional Block Diagram
    4. 8.4 Diagnostics
  9. 9 Device Configuration
    1. 9.1 Commands and Subcommands
    2. 9.2 Configuration Using OTP or Registers
    3. 9.3 Device Security
    4. 9.4 Scratchpad Memory
  10. 10Measurement Subsystem
    1. 10.1  Voltage Measurement
      1. 10.1.1 Voltage Measurement Schedule
      2. 10.1.2 Usage of VC Pins for Cells Versus Interconnect
      3. 10.1.3 Cell 1 Voltage Validation During SLEEP Mode
    2. 10.2  General Purpose ADCIN Functionality
    3. 10.3  Coulomb Counter and Digital Filters
    4. 10.4  Synchronized Voltage and Current Measurement
    5. 10.5  Internal Temperature Measurement
    6. 10.6  Thermistor Temperature Measurement
    7. 10.7  Factory Trim of Voltage ADC
    8. 10.8  Voltage Calibration (ADC Measurements)
    9. 10.9  Voltage Calibration (COV and CUV Protections)
    10. 10.10 Current Calibration
    11. 10.11 Temperature Calibration
  11. 11Primary and Secondary Protection Subsystems
    1. 11.1 Protections Overview
    2. 11.2 Primary Protections
    3. 11.3 Secondary Protections
    4. 11.4 High-Side NFET Drivers
    5. 11.5 Protection FETs Configuration and Control
      1. 11.5.1 FET Configuration
      2. 11.5.2 PRECHARGE and PREDISCHARGE Modes
    6. 11.6 Load Detect Functionality
  12. 12Device Hardware Features
    1. 12.1  Voltage References
    2. 12.2  ADC Multiplexer
    3. 12.3  LDOs
      1. 12.3.1 Preregulator Control
      2. 12.3.2 REG1 and REG2 LDO Controls
    4. 12.4  Standalone Versus Host Interface
    5. 12.5  Multifunction Pin Controls
    6. 12.6  RST_SHUT Pin Operation
    7. 12.7  CFETOFF, DFETOFF, BOTHOFF Pin Functionality
    8. 12.8  ALERT Pin Operation
    9. 12.9  DDSG and DCHG Pin Operation
    10. 12.10 Fuse Drive
    11. 12.11 Cell Open Wire
    12. 12.12 Low Frequency Oscillator
    13. 12.13 High Frequency Oscillator
  13. 13Device Functional Modes
    1. 13.1 Overview
    2. 13.2 NORMAL Mode
    3. 13.3 SLEEP Mode
    4. 13.4 DEEPSLEEP Mode
    5. 13.5 SHUTDOWN Mode
    6. 13.6 CONFIG_UPDATE Mode
  14. 14Serial Communications Interface
    1. 14.1 Serial Communications Overview
    2. 14.2 I2C Communications Subsystem
    3. 14.3 SPI Communications Interface
      1. 14.3.1 SPI Protocol
    4. 14.4 HDQ Communications Interface
  15. 15Cell Balancing
    1. 15.1 Cell Balancing Overview
  16. 16Application and Implementation
    1. 16.1 Application Information
    2. 16.2 Typical Applications
      1. 16.2.1 Design Requirements (Example)
      2. 16.2.2 Detailed Design Procedure
      3. 16.2.3 Application Performance Plot
      4. 16.2.4 Calibration Process
      5. 16.2.5 Design Example
    3. 16.3 Random Cell Connection Support
    4. 16.4 Startup Timing
    5. 16.5 FET Driver Turn-Off
    6. 16.6 Unused Pins
  17. 17Power Supply Requirements
  18. 18Layout
    1. 18.1 Layout Guidelines
    2. 18.2 Layout Example
  19. 19Device and Documentation Support
    1. 19.1 Third-Party Products Disclaimer
    2. 19.2 Documentation Support
      1. 19.2.1 Receiving Notification of Documentation Updates
    3. 19.3 Support Resources
    4. 19.4 Trademarks
    5. 19.5 Electrostatic Discharge Caution
    6. 19.6 Glossary
  20. 20Mechanical, Packaging, Orderable Information

Package Options

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

7.19 Analog-to-Digital Converter

Typical values stated where TA = 25°C and VBAT = 55.0 V, min/max values stated where TA = -40°C to 85°C and VBAT = 4.7 V to 55 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V(ADC_IN_CELLS) Input voltage range (differential cell input mode)(4) Internal reference (Vref = VREF1) –0.2 5.5 V
V(ADC_IN) Input voltage range (ADCIN measurement mode)(5) Internal reference (Vref = VREF1), applicable to ADCIN measurements using the TS1, TS2, TS3, ALERT, CFETOFF, DFETOFF, HDQ, DCHG, and DDSG pins –0.2 VREG18 V
V(ADC_IN_TS) Input voltage range (external thermistor measurement mode)(6) Regulator reference (Vref = VREG18), applicable to external thermistor measurements using the TS1, TS2, TS3, ALERT, CFETOFF, DFETOFF, HDQ, DCHG, and DDSG pins –0.2 VREG18 V
V(ADC_IN_DIV) Input voltage range (divider measurement mode)(7) Internal reference (Vref = VREF1), applicable to divider measurements using the VC10, PACK, and LD pins relative to VSS. –0.2 55 V
B(ADC_INL) Integral nonlinearity (when using VREF1 and differential cell voltage measurement mode at VC10 - VC9)(3) 16-bit, best fit over -0.1 V to 5.5 V –6.6 6.6 LSB(4)
16-bit, best fit over -0.2 V to 0.2 V –4 4 LSB(4)
B(ADC_DNL) Differential nonlinearity 16-bit, no missing codes, using differential cell voltage measurement at VC10-VC9 ±0.12 LSB(4)
B(ADC_OFF_CELL) Differential cell offset error 16-bit, uncalibrated, using VC10 - VC9 –2.75 3.5 LSB(4)
B(ADC_OFF) ADCIN offset error 16-bit, uncalibrated, using ADCIN mode on TS1 pin 0.53 LSB(5)
B(ADC_OFF_DIV) Divider offset error 16-bit, uncalibrated, using divider mode on PACK pin 0.17 LSB(7)
B(ADC_OFF_DRIFT_CELL) Differential cell offset error drift(3) Offset error measured 16-bit, post calibration, using VC10 - VC9.  Drift measured as change in offset over operating temperature range as compared to offset at 30°C. 0.004 0.07 LSB/°C(4)
B(ADC_GAIN) Gain Gain measured 16-bit, over ideal input voltage range, differential cell input mode on VC10 - VC9, uncalibrated. 5385 5406 5427 LSB/V(4)
B(ADC_GAIN_DRIFT) Gain drift(3) Gain measured 16-bit, over ideal input voltage range, differential cell input mode on VC10 - VC9, uncalibrated.  Drift value measured as change in gain over operating temperature range, compared to gain at 30°C. –0.25 0.025 0.25 LSB/V/°C(4)
R(ADC_IN_CELL) Effective input resistance(2) Differential cell input mode on VC10 - VC9(8) 3.0 MΩ
R(ADC_IN_LD) Effective input resistance Divider measurement on LD pin (only active while the LD pin is being measured) 2 MΩ
R(ADC_IN_DIV) Effective input resistance Divider measurement on VC10 and PACK pins (only active while the pin is being measured) 600 kΩ
B(ADC_RES) Code stability(1) (3) Single conversion, in NORMAL mode, Settings:Configuration:Power Config[FASTADC] = 0 13.5 15 bits
B(ADC_RES_FAST) Code stability in fast mode(1) Single conversion, in NORMAL mode, Settings:Configuration:Power Config[FASTADC] = 1 14 bits
t(ADC_CONV) Conversion-time Single conversion, in NORMAL mode, Settings:Configuration:Power Config[FASTADC] = 0 2.93 ms
t(ADC_CONV_FAST) Conversion-time in fast mode Single conversion, in NORMAL mode, Settings:Configuration:Power Config[FASTADC] = 1 1.46 ms
(1) Code stability is defined as the resolution such that the data exhibits 3-sigma variation within ±1-LSB.
(2) Specified by design
(3) Specified by characterization
(4) The 16-bit LSB size of the differential cell voltage measurement is given by 1 LSB = 5 x VREF1 / 2N-1 ≈ 5 x 1.212 V / 215 = 185 µV
(5) The 16-bit LSB size of the ADCIN voltage measurement is given by 1 LSB = 5 / 3 x VREF1 / 2N-1 ≈ 5 / 3 x 1.212 V / 215 = 62 µV
(6) The LSB size of the external thermistor voltage measurement when reported in 32-bit format is given by 1 LSB = 5 / 3 x VREG18 / 2N-1 ≈ 5 / 3 x 1.8 V / 223 = 358 nV
(7) The 16-bit LSB size of the divider voltage measurement is given by 1 LSB = 425 / 3 x VREF1 / 2N-1 ≈ 425 / 3 x 1.212 / 215 = 5.24 mV
(8) Average effective differential input resistance with device operating in NORMAL mode, cell balancing disabled, three or more thermistors in use, and a 5 V differential voltage applied.