SLUSAT0E October   2012  – 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  Electrical Characteristics: Supply Current
    6. 7.6  Electrical Characteristics: Digital Input and Output DC
    7. 7.7  Electrical Characteristics: Power-On Reset
    8. 7.8  Electrical Characteristics: 2.5-V LDO Regulator
    9. 7.9  Electrical Characteristics: Internal Clock Oscillators
    10. 7.10 Electrical Characteristics: Integrating ADC (Coulomb Counter) Characteristics
    11. 7.11 Electrical Characteristics: ADC (Temperature and Cell Voltage)
    12. 7.12 Electrical Characteristics: Data Flash Memory
    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
        1. 8.3.2.1  Load Mode
        2. 8.3.2.2  Load Select
        3. 8.3.2.3  Reserve Cap-mAh
        4. 8.3.2.4  Reserve Energy
        5. 8.3.2.5  Design Energy Scale
        6. 8.3.2.6  Dsg Current Threshold
        7. 8.3.2.7  Chg Current Threshold
        8. 8.3.2.8  Quit Current, Dsg Relax Time, Chg Relax Time, and Quit Relax Time
        9. 8.3.2.9  Qmax
        10. 8.3.2.10 Update Status
        11. 8.3.2.11 Avg I Last Run
        12. 8.3.2.12 Avg P Last Run
        13. 8.3.2.13 Delta Voltage
        14. 8.3.2.14 Ra Tables and Ra Filtering Related Parameters
        15. 8.3.2.15 MaxScaleBackGrid
        16. 8.3.2.16 Max DeltaV, Min DeltaV
        17. 8.3.2.17 Qmax Max Delta %
        18. 8.3.2.18 Fast Resistance Scaling
        19. 8.3.2.19 StateOfCharge() Smoothing
        20. 8.3.2.20 DeltaV Max Delta
        21. 8.3.2.21 Lifetime Data Logging Parameters
    4. 8.4 Device Functional Modes
      1. 8.4.1  System Control Function
        1. 8.4.1.1 SHUTDOWN Mode
        2. 8.4.1.2 INTERRUPT Mode
        3. 8.4.1.3 Battery Level Indication
        4. 8.4.1.4 Internal Short Detection
        5. 8.4.1.5 Tab Disconnection Detection
      2. 8.4.2  Temperature Measurement and the TS Input
      3. 8.4.3  Over-Temperature Indication
        1. 8.4.3.1 Over-Temperature: Charge
        2. 8.4.3.2 Over-Temperature: Discharge
      4. 8.4.4  Charging and Charge Termination Indication
        1. 8.4.4.1 Detection Charge Termination
        2. 8.4.4.2 Charge Inhibit
      5. 8.4.5  Power Modes
        1. 8.4.5.1 NORMAL Mode
        2. 8.4.5.2 SLEEP Mode
        3. 8.4.5.3 FULLSLEEP Mode
        4. 8.4.5.4 HIBERNATE Mode
      6. 8.4.6  Power Control
        1. 8.4.6.1 Reset Functions
        2. 8.4.6.2 Wake-Up Comparator
        3. 8.4.6.3 Flash Updates
      7. 8.4.7  Autocalibration
      8. 8.4.8  Communications
        1. 8.4.8.1 Authentication
        2. 8.4.8.2 Key Programming (Data Flash Key)
        3. 8.4.8.3 Key Programming (Secure Memory Key)
        4. 8.4.8.4 Executing An Authentication Query
      9. 8.4.9  HDQ Single-Pin Serial Interface
      10. 8.4.10 HDQ Host Interruption Feature
        1. 8.4.10.1 Low Battery Capacity
        2. 8.4.10.2 Temperature
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
        1. 8.5.1.1 I2C Time-Out
        2. 8.5.1.2 I2C Command Waiting Time
        3. 8.5.1.3 I2C Clock Stretching
      2. 8.5.2 Data Commands
        1. 8.5.2.1 Standard Data Commands
          1. 8.5.2.1.1  Control(): 0x00 and 0x01
            1. 8.5.2.1.1.1  CONTROL_STATUS: 0x0000
            2. 8.5.2.1.1.2  DEVICE_TYPE: 0x0001
            3. 8.5.2.1.1.3  FW_VERSION: 0x0002
            4. 8.5.2.1.1.4  HW_VERSION: 0x0003
            5. 8.5.2.1.1.5  RESET_DATA: 0x0005
            6. 8.5.2.1.1.6  PREV_MACWRITE: 0x0007
            7. 8.5.2.1.1.7  CHEM_ID: 0x0008
            8. 8.5.2.1.1.8  BOARD_OFFSET: 0x0009
            9. 8.5.2.1.1.9  CC_OFFSET: 0x000a
            10. 8.5.2.1.1.10 CC_OFFSET_SAVE: 0x000b
            11. 8.5.2.1.1.11 DF_VERSION: 0x000c
            12. 8.5.2.1.1.12 SET_FULLSLEEP: 0x0010
            13. 8.5.2.1.1.13 SET_HIBERNATE: 0x0011
            14. 8.5.2.1.1.14 CLEAR_HIBERNATE: 0x0012
            15. 8.5.2.1.1.15 SET_SHUTDOWN: 0x0013
            16. 8.5.2.1.1.16 CLEAR_SHUTDOWN: 0x0014
            17. 8.5.2.1.1.17 SET_HDQINTEN: 0x0015
            18. 8.5.2.1.1.18 CLEAR_HDQINTEN: 0x0016
            19. 8.5.2.1.1.19 STATIC_CHEM_DF_CHKSUM: 0x0017
            20. 8.5.2.1.1.20 SEALED: 0x0020
            21. 8.5.2.1.1.21 IT ENABLE: 0x0021
            22. 8.5.2.1.1.22 RESET: 0x0041
            23. 8.5.2.1.1.23 EXIT_CAL: 0x0080
            24. 8.5.2.1.1.24 Enter_cal: 0x0081
            25. 8.5.2.1.1.25 OFFSET_CAL: 0x0082
          2. 8.5.2.1.2  AtRate(): 0x02 and 0x03
          3. 8.5.2.1.3  UnfilteredSOC(): 0x04 And 0x05
          4. 8.5.2.1.4  Temperature(): 0x06 And 0x07
          5. 8.5.2.1.5  Voltage(): 0x08 And 0x09
          6. 8.5.2.1.6  Flags(): 0x0a And 0x0b
          7. 8.5.2.1.7  NominalAvailableCapacity(): 0x0c and 0x0d
          8. 8.5.2.1.8  FullAvailableCapacity(): 0x0e and 0x0f
          9. 8.5.2.1.9  RemainingCapacity(): 0x10 and 0x11
          10. 8.5.2.1.10 FullChargeCapacity(): 0x12 and 0x13
          11. 8.5.2.1.11 AverageCurrent(): 0x14 and 0x15
          12. 8.5.2.1.12 TimeToEmpty(): 0x16 And 0x17
          13. 8.5.2.1.13 FilteredFCC(): 0x18 And 0x19
          14. 8.5.2.1.14 StandbyCurrent(): 0x1a And 0x1b
          15. 8.5.2.1.15 UnfilteredFCC(): 0x1c And 0x1d
          16. 8.5.2.1.16 MaxLoadCurrent(): 0x1e And 0x1f
          17. 8.5.2.1.17 UnfilteredRM(): 0x20 And 0x21
          18. 8.5.2.1.18 FilteredRM(): 0x22 And 0x23
          19. 8.5.2.1.19 AveragePower(): 0x24 And 0x25
          20. 8.5.2.1.20 InternalTemperature(): 0x28 And 0x29
          21. 8.5.2.1.21 CycleCount(): 0x2a And 0x2b
          22. 8.5.2.1.22 StateOfCharge(): 0x2c And 0x2d
          23. 8.5.2.1.23 StateOfHealth(): 0x2e And 0x2f
          24. 8.5.2.1.24 PassedCharge(): 0x34 And 0x35
          25. 8.5.2.1.25 Dod0(): 0x36 And 0x37
          26. 8.5.2.1.26 SelfDischargeCurrent(): 0x38 And 0x39
      3. 8.5.3 Extended Data Commands
        1. 8.5.3.1  PackConfig(): 0x3a and 0x3b
        2. 8.5.3.2  DesignCapacity(): 0x3c And 0x3d
        3. 8.5.3.3  DataFlashClass(): 0x3e
        4. 8.5.3.4  DataFlashBlock(): 0x3f
        5. 8.5.3.5  BlockData(): 0x40 Through 0x5f
        6. 8.5.3.6  BlockDataChecksum(): 0x60
        7. 8.5.3.7  BlockDataControl(): 0x61
        8. 8.5.3.8  DeviceNameLength(): 0x62
        9. 8.5.3.9  DeviceName(): 0x63 Through 0x6c
        10. 8.5.3.10 Reserved: 0x6a Through 0x7f
      4. 8.5.4 Data Flash Interface
        1. 8.5.4.1 Accessing the Data Flash
        2. 8.5.4.2 Manufacturer Information Blocks
      5. 8.5.5 Access Modes
      6. 8.5.6 Sealing and Unsealing Data Flash
      7. 8.5.7 Data Flash Summary
    6. 8.6 Register Maps
      1. 8.6.1 Pack Configuration Register
        1. Table 1. Pack Configuration Bit Definition
      2. 8.6.2 Pack Configuration B Register
        1. Table 2. Pack Configuration B Bit Definition
      3. 8.6.3 Pack Configuration C Register
        1. Table 3. Pack Configuration C Bit Definition
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      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. 9.2.3 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 bq27545-G1 measures the cell voltage, temperature, and current to determine battery SOC based on Impedance Track algorithm (see the Theory and Implementation of Impedance Track Battery Fuel-Gauging Algorithm Application Report [SLUA450] for more information). The bq27545-G1 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 charge passing through the battery, the battery’s 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 manufacturers' data sheet multiplied by the number of parallel cells. It is also used for the value in Design Capacity. The bq27545-G1 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.

The bq27545-G1 has two flags accessed by the Flags() function that warns when the battery’s SOC has fallen to critical levels. When RemainingCapacity() falls below the first capacity threshold, specified in SOC1 Set Threshold, the [SOC1] (State of Charge Initial) flag is set. The flag is cleared once RemainingCapacity() rises above SOC1 Clear Threshold. All units are in mAh.

When RemainingCapacity() falls below the second capacity threshold, SOCF Set Threshold, the [SOCF] (State of Charge Final) flag is set, serving as a final discharge warning. If SOCF Set Threshold = –1, the flag is inoperative during discharge. Similarly, when RemainingCapacity() rises above SOCF Clear Threshold and the [SOCF] flag has already been set, the [SOCF] flag is cleared. All units are in mAh.

The bq27545-G1 has two additional flags accessed by the Flags() function that warns of internal battery conditions. The fuel gauge monitors the cell voltage during relaxed conditions to determine if an internal short has been detected. When this condition occurs, [ISD] will be set. The bq27545-G1 also has the capability of detecting when a tab has been disconnected in a 2-cell parallel system by actively monitoring the SOH. When this conditions occurs, [TDD] will be set.