SLUSBF2C July   2013  – August 2015

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
    5. 7.5  Power-On Reset
    6. 7.6  2.5-V LDO Regulator
    7. 7.7  Charger Attachment and Removal Detection
    8. 7.8  Voltage Doubler
    9. 7.9  Overvoltage Protection (OVP)
    10. 7.10 Undervoltage Protection (UVP)
    11. 7.11 Overcurrent in Discharge (OCD)
    12. 7.12 Overcurrent in Charge (OCC)
    13. 7.13 Short-Circuit in Discharge (SCD)
    14. 7.14 Low-Voltage Charging
    15. 7.15 Internal Temperature Sensor Characteristics
    16. 7.16 Internal Clock Oscillators
    17. 7.17 Integrating ADC (Coulomb Counter) Characteristics
    18. 7.18 ADC (Temperature and Cell Voltage) Characteristics
    19. 7.19 Data Flash Memory Characteristics
    20. 7.20 I2C-Compatible Interface Timing Characteristics
    21. 7.21 HDQ Communication Timing Characteristics
    22. 7.22 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Configuration
      2. 8.3.2 Fuel Gauging
      3. 8.3.3 Wake-Up Comparator
      4. 8.3.4 Battery Parameter Measurements
        1. 8.3.4.1 Charge and Discharge Counting
        2. 8.3.4.2 Voltage
        3. 8.3.4.3 Current
        4. 8.3.4.4 Auto-Calibration
        5. 8.3.4.5 Temperature
      5. 8.3.5 Communications
        1. 8.3.5.1 HDQ Single-Pin Serial Interface
        2. 8.3.5.2 HDQ Host Interruption
          1. 8.3.5.2.1 Low Battery Capacity
          2. 8.3.5.2.2 Temperature
        3. 8.3.5.3 I2C Interface
          1. 8.3.5.3.1 I2C Time Out
          2. 8.3.5.3.2 I2C Command Waiting Time
    4. 8.4 Device Functional Modes
      1. 8.4.1 NORMAL Mode
      2. 8.4.2 SLEEP Mode
      3. 8.4.3 FULLSLEEP Mode
      4. 8.4.4 Battery Protector Description
        1. 8.4.4.1 High-Side N-Channel FET Charge and Discharge FET Drive
        2. 8.4.4.2 Operating Modes
          1. 8.4.4.2.1 VIRTUAL SHUTDOWN Mode
            1. 8.4.4.2.1.1 ANALOG SHUTDOWN Mode
            2. 8.4.4.2.1.2 LOW-VOLTAGE CHARGING Mode
          2. 8.4.4.2.2 UNDERVOLTAGE FAULT Mode
          3. 8.4.4.2.3 NORMAL Mode
          4. 8.4.4.2.4 SHUTDOWN WAIT Mode
          5. 8.4.4.2.5 OVERCURRENT IN DISCHARGE (OCD) and SHORT-CIRCUIT IN DISCHARGE (SCD) FAULT Mode
          6. 8.4.4.2.6 OVERCURRENT IN CHARGE (OCC) FAULT Mode
          7. 8.4.4.2.7 OVERVOLTAGE PROTECTION (OVP) FAULT Mode
        3. 8.4.4.3 Firmware Control of Protector
      5. 8.4.5 OVERTEMPERATURE FAULT Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Pack-Side, Single-Cell Li-Ion Fuel Gauge and Protector
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  BAT Voltage Sense Input
          2. 9.2.1.2.2  SRP and SRN Current Sense Inputs
          3. 9.2.1.2.3  Sense Resistor Selection
          4. 9.2.1.2.4  TS Temperature Sense Input
          5. 9.2.1.2.5  Thermistor Selection
          6. 9.2.1.2.6  VPWR Power Supply Input Filtering
          7. 9.2.1.2.7  REG25 LDO Output Filtering
          8. 9.2.1.2.8  Communication Interface Lines
          9. 9.2.1.2.9  PACKP Voltage Sense Input
          10. 9.2.1.2.10 CHG and DSG Charge Pump Voltage Outputs
          11. 9.2.1.2.11 N-Channel FET Selection
          12. 9.2.1.2.12 Additional ESD Protection Components
        3. 9.2.1.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Li-Ion Cell Connections
      2. 11.1.2 Sense Resistor Connections
      3. 11.1.3 Thermistor Connections
      4. 11.1.4 FET Connections
      5. 11.1.5 ESD Component Connections
      6. 11.1.6 High Current and Low Current Path Separation
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

6 Pin Configuration and Functions

YZF Package
15-Pin DSBGA
bq27741-G1 pinout.gif

Pin Functions

PIN I/O(1) DESCRIPTION
NAME NO.
BAT C2 IA Cell-voltage measurement input. ADC input
CHG A2 O External high-side N-channel charge FET driver
DSG A3 O External high-side N-channel discharge FET driver
HDQ D2 IO HDQ serial communications line. Open-drain
PACKP B3 IA Pack voltage measurement input for protector operation
NC B2 IO Not used. Reserved for future GPIO. Recommended to connect to GND.
RC2 D3 IO General purpose IO. Push-pull output
REG25 E1 P Regulator output and bq27741-G1 processor power. Decouple with 1-µF ceramic capacitor to VSS.
SCL E3 IO Slave I2C serial communications clock input line for communication with system. Use with 10-kΩ pullup resistor (typical).
SDA C3 IO Slave I2C serial communications data line for communication with system. Open-drain I/O. Use with 10-kΩ pullup resistor (typical).
SRN B1 IA Analog input pin connected to the internal coulomb counter where SRN is nearest the CELL+ connection. Connect to sense resistor.
SRP A1 IA Analog input pin connected to the internal coulomb counter where SRP is nearest the PACK+ connection. Connect to sense resistor.
VPWR C1 P Power input. Decouple with 0.1-µF ceramic capacitor to VSS.
VSS D1 P Device ground
TS E2 IA Pack thermistor voltage sense (use 103AT-type thermistor). ADC input
(1) IO = Digital input-output, IA = Analog input, P = Power connection, O = Output

Table 1. Default Configuration

OVERVOLTAGE PROTECTION (VOVP) UNDERVOLTAGE PROTECTION (VUVP) OVERCURRENT IN DISCHARGE (VOCD) OVERCURRENT IN CHARGE (VOCC) SHORT CIRCUIT IN DISCHARGE (Vscd)
4.390 V 2.407 V 34.4 mV 20 mV 74.6 mV
OVERVOLTAGE PROTECTION DELAY (tOVP) UNDERVOLTAGE PROTECTION DELAY (tUVP) OVERCURRENT IN DISCHARGE DELAY (tOCD) OVERCURRENT IN CHARGE DELAY (tOCC) SHORT CIRCUIT IN DISCHARGE DELAY (tscd)
1 s 31.25 ms 31.25 ms 7.8125 ms 312.5 µs