SLUSC53B May   2015  – May 2018

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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  Supply Current
    6. 7.6  Digital Input and Output DC Characteristics
    7. 7.7  Power-On Reset
    8. 7.8  2.5-V LDO Regulator
    9. 7.9  Internal Clock Oscillators
    10. 7.10 Integrating ADC (Coulomb Counter) Characteristics
    11. 7.11 ADC (Temperature and Cell Voltage) Characteristics
    12. 7.12 Data Flash Memory Characteristics
    13. 7.13 HDQ Communication Timing Characteristics
    14. 7.14 I2C-Compatible Interface Timing Characteristics
    15. 7.15 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 Fuel Gauging
      2. 8.3.2 Impedance Track Variables
      3. 8.3.3 Power Control
        1. 8.3.3.1 Reset Functions
        2. 8.3.3.2 Wake-Up Comparator
        3. 8.3.3.3 Flash Updates
      4. 8.3.4 Autocalibration
      5. 8.3.5 Communications
        1. 8.3.5.1 Authentication
        2. 8.3.5.2 Key Programming (Data Flash Key)
        3. 8.3.5.3 Key Programming (Secure Memory Key)
        4. 8.3.5.4 Executing an Authentication Query
        5. 8.3.5.5 HDQ Single-Pin Serial Interface
        6. 8.3.5.6 HDQ Host Interruption Feature
          1. 8.3.5.6.1 Low Battery Capacity
          2. 8.3.5.6.2 Temperature
        7. 8.3.5.7 I2C Interface
          1. 8.3.5.7.1 I2C Time Out
          2. 8.3.5.7.2 I2C Command Waiting Time
          3. 8.3.5.7.3 I2C Clock Stretching
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power Modes
        1. 8.4.1.1 NORMAL Mode
        2. 8.4.1.2 SLEEP Mode
        3. 8.4.1.3 FULLSLEEP Mode
        4. 8.4.1.4 HIBERNATE Mode
      2. 8.4.2 System Control Function
        1. 8.4.2.1 SHUTDOWN Mode
        2. 8.4.2.2 INTERRUPT Mode
      3. 8.4.3 Security Modes
        1. 8.4.3.1 Sealing and Unsealing Data Flash
    5. 8.5 Programming
      1. 8.5.1 Standard Data Commands
        1. 8.5.1.1 Control(): 0x00 and 0x01
    6. 8.6 Register Maps
      1. 8.6.1 Pack Configuration Register
      2. 8.6.2 Pack Configuration B Register
      3. 8.6.3 Pack Configuration C Register
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 BAT Voltage Sense Input
        2. 9.2.2.2 SRP and SRN Current Sense Inputs
        3. 9.2.2.3 Sense Resistor Selection
        4. 9.2.2.4 TS Temperature Sense Input
        5. 9.2.2.5 Thermistor Selection
        6. 9.2.2.6 REGIN Power Supply Input Filtering
        7. 9.2.2.7 VCC LDO Output Filtering
    3. 9.3 Application Curves
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Decoupling
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Sense Resistor Connections
      2. 11.1.2 Thermistor Connections
      3. 11.1.3 High-Current and Low-Current Path Separation
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.1 Fuel Gauging

The bq27546-G1 fuel gauge measures the cell voltage, temperature, and current to determine battery SOC based on the Impedance Track algorithm. (For more information, refer to the Theory and Implementation of Impedance Track Battery Fuel-Gauging Algorithm Application Report [SLUA450].) The device monitors charge and discharge activity by sensing the voltage across a small-value resistor (5-mΩ to 20-mΩ typical) between the SRP and SRN pins and in series with the cell. By integrating the charge passing through the battery, the battery SOC is adjusted during battery charge or discharge.

The total battery capacity is found by comparing states of charge before and after applying the load with the amount of charge passed. When an application load is applied, the impedance of the cell is measured by comparing the OCV obtained from a predefined function for present SOC with the measured voltage under load. Measurements of OCV and charge integration determine chemical state of charge and chemical capacity (Qmax). The initial Qmax values are taken from a cell manufacturer's data sheet multiplied by the number of parallel cells. It is also used for the value in Design Capacity. The fuel gauge acquires and updates the battery-impedance profile during normal battery usage. It uses this profile, along with SOC and the Qmax value, to determine FullChargeCapacity() and StateOfCharge(), specifically for the present load and temperature. FullChargeCapacity() is reported as capacity available from a fully charged battery under the present load and temperature until Voltage() reaches the Terminate Voltage. NominalAvailableCapacity() and FullAvailableCapacity() are the uncompensated (no or light load) versions of RemainingCapacity() and FullChargeCapacity(), respectively.