SLUSBV9D March   2014  – January 2018

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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  Power-On Reset
    6. 6.6  2.5-V LDO Regulator
    7. 6.7  Charger Attachment and Removal Detection
    8. 6.8  CHG and DSG FET Drive
    9. 6.9  Overvoltage Protection (OVP)
    10. 6.10 Undervoltage Protection (UVP)
    11. 6.11 Overcurrent in Discharge (OCD)
    12. 6.12 Overcurrent in Charge (OCC)
    13. 6.13 Short-Circuit in Discharge (SCD)
    14. 6.14 Low Voltage Charging
    15. 6.15 Internal Temperature Sensor Characteristics
    16. 6.16 High-Frequency Oscillator
    17. 6.17 Low-Frequency Oscillator
    18. 6.18 Integrating ADC (Coulomb Counter) Characteristics
    19. 6.19 ADC (Temperature and Cell Voltage) Characteristics
    20. 6.20 Data Flash Memory Characteristics
    21. 6.21 Timing Requirements
    22. 6.22 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Configuration
      2. 7.3.2 Fuel Gauging
      3. 7.3.3 Power Modes
        1. 7.3.3.1 NORMAL Mode
        2. 7.3.3.2 SLEEP Mode
        3. 7.3.3.3 FULLSLEEP Mode
      4. 7.3.4 Li-Ion Battery Protector Description
        1. 7.3.4.1 High-Side NFET Charge and Discharge FET Drive
        2. 7.3.4.2 Protector Configuration
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operating Modes
        1. 7.4.1.1 NORMAL Mode
        2. 7.4.1.2 OVERVOLTAGE Mode
        3. 7.4.1.3 UNDERVOLTAGE Mode
        4. 7.4.1.4 OVERCURRENT IN CHARGE Mode
        5. 7.4.1.5 OVERCURRENT IN DISCHARGE and SHORT-CIRCUIT IN DISCHARGE Mode
        6. 7.4.1.6 SHUTDOWN WAIT Mode
          1. 7.4.1.6.1 ANALOG SHUTDOWN State
        7. 7.4.1.7 LOW VOLTAGE CHARGING State
      2. 7.4.2 Firmware Control of Protector
      3. 7.4.3 OVERTEMPERATURE FAULT Mode
      4. 7.4.4 Wake-Up Comparator
    5. 7.5 Battery Parameter Measurements
      1. 7.5.1 Charge and Discharge Counting
      2. 7.5.2 Voltage
      3. 7.5.3 Current
      4. 7.5.4 Auto-Calibration
      5. 7.5.5 Temperature
    6. 7.6 Communications
      1. 7.6.1 HDQ Single-Pin Serial Interface
      2. 7.6.2 I2C Interface
        1. 7.6.2.1 I2C Time Out
        2. 7.6.2.2 I2C Command Waiting Time
    7. 7.7 Standard Data Commands
      1. 7.7.1 Control(): 0x00 and 0x01
    8. 7.8 Extended Data Commands
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Pack-Side, Single-Cell Li-Ion Fuel Gauge and Protector
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1  BAT Voltage Sense Input
        2. 8.2.3.2  SRP and SRN Current Sense Inputs
        3. 8.2.3.3  Sense Resistor Selection
        4. 8.2.3.4  TS Temperature Sense Input
        5. 8.2.3.5  Thermistor Selection
        6. 8.2.3.6  VPWR Power Supply Input Filtering
        7. 8.2.3.7  REG25 LDO Output Filtering
        8. 8.2.3.8  Communication Interface Lines
        9. 8.2.3.9  PACKP Voltage Sense Input
        10. 8.2.3.10 CHG and DSG Charge Pump Voltage Outputs
        11. 8.2.3.11 NFET Selection
        12. 8.2.3.12 Additional ESD Protection Components
      4. 8.2.4 Application Curves
  9. 9 Power Supply Recommendation
    1. 9.1 Power Supply Decoupling
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Li-Ion Cell Connections
      2. 10.1.2 Sense Resistor Connections
      3. 10.1.3 Thermistor Connections
      4. 10.1.4 FET Connections
      5. 10.1.5 ESD Component Connections
      6. 10.1.6 High Current and Low Current Path Separation
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receive Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.6.2 I2C Interface

The fuel gauge supports the standard I2C read, incremental read, one-byte write quick read, and functions. The 7-bit device address (ADDR) is the most significant 7 bits of the hex address and is fixed as 1010101. The 8-bit device address is therefore 0xAA or 0xAB for write or read, respectively.

bq27742-G1 I2C_Interface_1.gif
a. 1-byte write; b. Quick read; c. 1-byte read; Incremental read (S = Start, Sr = Repeated Start, A = Acknowledge, N = No Acknowledge, and P = Stop)
Figure 16. Supported I2C Formats

The quick read returns data at the address indicated by the address pointer. The address pointer, a register internal to the I2C communication engine, increments whenever data is acknowledged by the fuel gauge or the I2C master. Quick writes function in the same manner and are a convenient means of sending multiple bytes to consecutive command locations (such as two-byte commands that require two bytes of data).

Attempt to write a read-only address (NACK after data sent by master):

bq27742-G1 I2C_Interface_2.gif

Attempt to read an address above 0x7F (NACK command):

bq27742-G1 I2C_Interface_3.gif

Attempt at incremental writes (NACK all extra data bytes sent):

bq27742-G1 I2C_Interface_4.gif

Incremental read at the maximum allowed read address:

bq27742-G1 I2C_Interface_5.gifFigure 17. I2C Interfaces

The I2C engine releases both SDA and SCL if the I2C bus is held low for t(BUSERR). If the fuel gauge was holding the lines, releasing them frees the master to drive the lines. If an external condition is holding either of the lines low, the I2C engine enters the low-power SLEEP mode.