SLUUBD4A April   2016  – November 2022 BQ27220

 

  1.   Read This First
    1. 1.1 About This Manual
    2. 1.2 Formatting conventions used in this document:
    3. 1.3 Related Documentation from Texas Instruments
    4. 1.4 Trademarks
  2. 2General Description
    1. 2.1 Gas Gauging
      1. 2.1.1  CEDV Gas Gauging Operational Overview
      2. 2.1.2  Main Fuel Gauge Registers
      3. 2.1.3  Capacity Learning (FCC Update) and Qualified Discharge
      4. 2.1.4  End-of-Discharge Thresholds and Capacity Correction
      5. 2.1.5  EDV Discharge Rate and Temperature Compensation
      6. 2.1.6  EDV Age Factor
      7. 2.1.7  Self-Discharge
      8. 2.1.8  Battery Electronic Load Compensation
      9. 2.1.9  CEDV Configuration
      10. 2.1.10 Initial Battery Capacity at Device Reset
      11. 2.1.11 Fuel Gauge Operating Modes
      12. 2.1.12 Qmax
      13. 2.1.13 CEDV Smoothing
  3. 3Standard Data Commands
    1. 3.1  Standard Commands
    2. 3.2  Control()/CONTROL_STATUS(): 0x00 and 0x01
      1. 3.2.1  CONTROL_STATUS: 0x0000
      2. 3.2.2  DEVICE_NUMBER: 0x0001
      3. 3.2.3  FW_VERSION: 0x0002
      4. 3.2.4  HW_VERSION: 0x0003
      5. 3.2.5  BOARD_OFFSET: 0x0009
      6. 3.2.6  CC_OFFSET: 0x000A
      7. 3.2.7  CC_OFFSET_SAVE: 0x000B
      8. 3.2.8  OCV_CMD: 0x000C
      9. 3.2.9  BAT_INSERT: 0x000D
      10. 3.2.10 BAT_REMOVE: 0x000E
      11. 3.2.11 SET_SNOOZE: 0x0013
      12. 3.2.12 CLEAR_SNOOZE: 0x0014
      13. 3.2.13 SET_PROFILE_1/2/3/4/5/6: 0x0015–0x001A
      14. 3.2.14 CAL_TOGGLE: 0x002D
      15. 3.2.15 SEALED: 0x0030
      16. 3.2.16 RESET: 0x0041
      17. 3.2.17 OPERATION_STATUS: 0x0054
      18. 3.2.18 GaugingStatus: 0x0056
      19. 3.2.19 EXIT_ CAL: 0x0080
      20. 3.2.20 ENTER_CAL: 0x0081
      21. 3.2.21 ENTER_CFG_UPDATE: 0x0090
      22. 3.2.22 EXIT_CFG_UPDATE_REINIT: 0x0091
      23. 3.2.23 EXIT_CFG_UPDATE: 0x0092
      24. 3.2.24 ENTER_ROM: 0x0F00
    3. 3.3  AtRate(): 0x02 and 0x03
    4. 3.4  AtRateTimeToEmpty(): 0x04 and 0x05
    5. 3.5  Temperature(): 0x06 and 0x07
    6. 3.6  Voltage(): 0x08 and 0x09
    7. 3.7  BatteryStatus(): 0x0A and 0x0B
    8. 3.8  Current(): 0x0C and 0x0D
    9. 3.9  RemainingCapacity(): 0x10 and 0x11
    10. 3.10 FullChargeCapacity(): 0x12 and 0x13
    11. 3.11 TimeToEmpty(): 0x16 and 0x17
    12. 3.12 TimeToFull(): 0x18 and 0x19
    13. 3.13 StandbyCurrent(): 0x1A and 0x1B
    14. 3.14 StandbyTimeToEmpty(): 0x1C and 0x1D
    15. 3.15 MaxLoadCurrent(): 0x1E and 0x1F
    16. 3.16 MaxLoadTimeToEmpty(): 0x20 and 0x21
    17. 3.17 RawCoulombCount(): 0x22 and 0x23
    18. 3.18 AveragePower(): 0x24 and 0x25
    19. 3.19 InternalTemperature(): 0x28 and 0x29
    20. 3.20 CycleCount(): 0x2A and 0x2B
    21. 3.21 StateOfCharge(): 0x2C and 0x2D
    22. 3.22 StateOfHealth(): 0x2E and 0x2F
    23. 3.23 ChargingVoltage(): 0x30 and 0x31
    24. 3.24 ChargingCurrent(): 0x32 and 0x33
    25. 3.25 BTPDischargeSet(): 0x34 and 0x35
    26. 3.26 BTPChargeSet(): 0x36 and 0x37
    27. 3.27 OperationStatus(): 0x3A and 0x3B
    28. 3.28 DesignCapacity(): 0x3C and 0x3D
    29. 3.29 MACData(): 0x40 through 0x5F
    30. 3.30 MACDataSum(): 0x60
    31. 3.31 MACDataLen(): 0x61
    32. 3.32 AnalogCount(): 0x79
    33. 3.33 RawCurrent(): 0x7A and 0x7B
    34. 3.34 RawVoltage(): 0x7C and 0x7D
  4. 4Data Memory Interface
    1. 4.1 Accessing the Data Memory
    2. 4.2 Device Access Modes
    3. 4.3 Sealing and Unsealing Data Memory Access
    4. 4.4 Data Memory Summary
  5. 5Functional Description
    1. 5.1 Device Configuration
      1. 5.1.1 CEDV Smoothing Config Register
      2. 5.1.2 Operation Configuration A (Operation Config A) Register
      3. 5.1.3 Operation Configuration B (Operation Config B) Register
    2. 5.2 External Pin Functions
      1. 5.2.1 Pin Function Code (PFC) Descriptions
      2. 5.2.2 Battery Presence Detection Using the BIN/TOUT Pin
      3. 5.2.3 SOC_INT Pin Behavior
      4. 5.2.4 Power Path Control With the BAT_GD Pin
      5. 5.2.5 Battery Trip Point (BTP) Interrupts
      6. 5.2.6 Wake-Up Comparator
      7. 5.2.7 Autocalibration
    3. 5.3 Temperature Measurement
      1. 5.3.1 Overtemperature Indication
        1. 5.3.1.1 Overtemperature: Charge
        2. 5.3.1.2 Overtemperature: Discharge
    4. 5.4 Charging and Charge Termination Indication
      1. 5.4.1 Detecting Charge Termination
      2. 5.4.2 Charge Inhibit
    5. 5.5 Power Modes
      1. 5.5.1 NORMAL Mode
      2. 5.5.2 SLEEP Mode
    6. 5.6 CONFIG UPDATE Mode
    7. 5.7 BAT INSERT CHECK Mode
    8. 5.8 Application-Specific Information
      1. 5.8.1 Battery Profile Storage and Selection
      2. 5.8.2 First OCV Measurement
    9. 5.9 Additional Data Memory Parameter Descriptions
      1. 5.9.1  Calibration
        1. 5.9.1.1 CC Gain
        2. 5.9.1.2 CC Delta
      2. 5.9.2  Coulomb Counter Offset
      3. 5.9.3  Board Offset
      4. 5.9.4  Int Temp Offset
      5. 5.9.5  Ext Temp Offset
      6. 5.9.6  Pack VOffset
      7. 5.9.7  Internal Temp Model
      8. 5.9.8  Ext a Coef and Ext b Coef
      9. 5.9.9  Filter
      10. 5.9.10 Deadband
      11. 5.9.11 CC Deadband
      12. 5.9.12 SOC Flag Configuration A (SOC Flag Config A) Register
      13. 5.9.13 SOC Flag Configuration B (SOC Flag Config B) Register
      14. 5.9.14 CEDV Gauging Configuration (CEDV Config) Register
      15. 5.9.15 EMF
      16. 5.9.16 C0
      17. 5.9.17 R0
      18. 5.9.18 T0
      19. 5.9.19 R1
      20. 5.9.20 TC
      21. 5.9.21 C1
      22. 5.9.22 Age Factor
      23. 5.9.23 Fixed EDV0
      24. 5.9.24 Fixed EDV1
      25. 5.9.25 Fixed EDV2
      26. 5.9.26 Battery Low %
      27. 5.9.27 Low Temp Learning
      28. 5.9.28 Overload Current
      29. 5.9.29 Self Discharge Rate
      30. 5.9.30 Electronic Load
      31. 5.9.31 Near Full
      32. 5.9.32 Reserve Capacity
      33. 5.9.33 Charge Efficiency
      34. 5.9.34 Discharge Efficiency
      35. 5.9.35 Qmax Cell 1 and Qmax Pack
      36. 5.9.36 Learned Full Charge Capacity
      37. 5.9.37 DOD at EDV2
      38. 5.9.38 Cycle Count
      39. 5.9.39 Design Capacity
      40. 5.9.40 Design Voltage
      41. 5.9.41 Cycle Count %
      42. 5.9.42 Charge Inhibit Temp Low
      43. 5.9.43 Charge Inhibit Temp High
      44. 5.9.44 Temp Hys
      45. 5.9.45 Fast Charge Current
      46. 5.9.46 Charging Voltage
      47. 5.9.47 Taper Current
      48. 5.9.48 Taper Voltage
      49. 5.9.49 SOC Delta
      50. 5.9.50 Clock Control Register
      51. 5.9.51 Sleep Current
      52. 5.9.52 Offset Calibration Inhibit Temperature Low
      53. 5.9.53 Offset Calibration Inhibit Temperature High
      54. 5.9.54 Sleep Voltage Time
      55. 5.9.55 Sleep Current Time
      56. 5.9.56 Dsg Current Threshold
      57. 5.9.57 Chg Current Threshold
      58. 5.9.58 Quit Current
      59. 5.9.59 Dsg Relax Time
      60. 5.9.60 Chg Relax Time
      61. 5.9.61 Quit Relax Time
      62. 5.9.62 OT Charge
        1. 5.9.62.1 OT Charge Time
      63. 5.9.63 OT Chg Recovery
      64. 5.9.64 OT Discharge
        1. 5.9.64.1 OT Discharge Time
      65. 5.9.65 OT Dsg Recovery
      66. 5.9.66 Initial Standby Current
      67. 5.9.67 Default Temperature
      68. 5.9.68 Device Name
      69. 5.9.69 System Down Set Voltage
      70. 5.9.70 System Down Set Voltage Time
      71. 5.9.71 System Down Clear Voltage
      72. 5.9.72 Full Reset Counter
      73. 5.9.73 Reset Counter Watchdog
  6. 6Communications
    1. 6.1 I2C Interface
    2. 6.2 I2C Time Out
    3. 6.3 I2C Command Waiting Time
    4. 6.4 I2C Clock Stretching
  7. 7Application Examples
    1. 7.1 Data Memory Parameter Update Example
  8. 8Open-Circuit Voltage Measurement Background
    1. 8.1 Background
      1. 8.1.1 OCV Qualification and Calculation
      2. 8.1.2 OCV Calculation Assumption
      3. 8.1.3 OCV Timing
    2. 8.2 OCV Timing and OCV_CMD Use Recommendations
      1. 8.2.1 ACTIVE Mode (Fuel Gauge Is Not in SLEEP Mode)
      2. 8.2.2 SLEEP Mode
      3. 8.2.3 Initial OCV – POR
  9. 9Updating BQ27220 Configuration Parameters
    1. 9.1  Gauge Mode FlashStream (gm.fs) Files
      1. 9.1.1 Write Command
      2. 9.1.2 Read and Compare Command
      3. 9.1.3 Wait Command
      4. 9.1.4 CONFIG UPDATE Mode
    2. 9.2  OTP Mode FlashStream (ot.fs) Files
      1. 9.2.1 Write Command
      2. 9.2.2 Read and Compare Command
      3. 9.2.3 Wait Command
      4. 9.2.4 CONFIG UPDATE Mode
    3. 9.3  Programming Instructions
      1. 9.3.1 Using gm.fs Files
      2. 9.3.2 Using ot.fs Files
    4. 9.4  General Setup and Software Installation to Program OTP
    5. 9.5  Launch BQStudio Software
    6. 9.6  Load .GG File
    7. 9.7  Confirm or Update Data Memory Parameters
    8. 9.8  Save .OTFS File
    9. 9.9  Launch SmartFlash Software
    10. 9.10 Open Ot.fs File
    11. 9.11 Program OTP
    12. 9.12 Confirm Success
  10.   A Battery Gauge Glossary
    1.     A.1 Glossary
  11.   B Revision History

4.1 Accessing the Data Memory

The Data Memory contains initialization, default, cell status, calibration, configuration, and user information. Most Data Memory parameters reside in volatile RAM initialized by associated parameters from ROM. However, some Data Memory parameters are directly accessed from ROM and do not have an associated RAM copy. The Data Memory can be accessed in several different ways, depending in which mode the fuel gauge is operating and what data is being accessed.

Commonly accessed Data Memory locations frequently read by a system are conveniently accessed through specific instructions already described in Chapter 5, Extended Data Commands. These commands are available when the fuel gauge is either in UNSEALED or SEALED mode. Most Data Memory locations, however, are only accessible in the UNSEALED mode by use of the evaluation software or by Data Memory block transfers. These locations should be optimized and/or fixed during the development and manufacturing processes. They become part of a golden image file and then can be written to multiple battery packs. Once established, the values generally remain unchanged during end-equipment operation.

To access Data Memory locations individually, the block containing the desired Data Memory location(s) must be transferred to the command register locations, where they can be read to the system or changed directly. This is accomplished by sending the set-up command BlockDataControl() (0x61) with data 0x00. Up to 32 bytes of data can be read directly from the BlockData() (0x40 through 0x5F), externally altered, then rewritten to the BlockData()command space. Alternatively, specific locations can be read, altered, and rewritten if their corresponding offsets index into the BlockData() command space. Finally, the data residing in the command space is transferred to Data Memory, once the correct checksum for the whole block is written to BlockDataChecksum() (0x60). Occasionally, a Data Memory class is larger than the 32-byte block size. In this case, the BlockData() command designates in which 32-byte block the desired locations reside. The correct command address is then given by 0x40 + offset modulo 32. For an example of this type of Data Memory access, see Section 4.3.

Reading and writing subclass data are block operations up to 32 bytes in length. During a write, if the data length exceeds the maximum block size, then the data is ignored. None of the data written to memory is bounded by the fuel gauge—the values are not rejected by the fuel gauge. Writing an incorrect value may result in incorrect operation due to firmware program interpretation of the invalid data. The written data is not persistent, so a POR does resolve the fault.