TIDUF20B December   2022  – July 2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Configure This Design for Different Use Cases
      2. 2.2.2 Auxiliary Power Strategy
      3. 2.2.3 High-Side N-Channel MOSFET
      4. 2.2.4 Stacked AFE Communication
      5. 2.2.5 Thermistor Multiplexer
      6. 2.2.6 CAN Stacking
    3. 2.3 Highlighted Products
      1. 2.3.1  BQ76972
      2. 2.3.2  MSPM0G3519
      3. 2.3.3  UCC334xx
      4. 2.3.4  LM5168
      5. 2.3.5  ISO1640
      6. 2.3.6  ISO1042
      7. 2.3.7  ISO1410
      8. 2.3.8  TPS7A24
      9. 2.3.9  TMP61
      10. 2.3.10 TPD2E007
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software Requirements
      1. 3.2.1 Getting Started MSPM0 Software
        1. 3.2.1.1 Download and Install Software Required for Board Test
        2. 3.2.1.2 Import the Project Into CCS
        3. 3.2.1.3 Compile the Project
        4. 3.2.1.4 Download Image and Run
      2. 3.2.2 Software Function List
        1. 3.2.2.1 Driverlib Function List
          1.        CAN_ID_Init_on_Startup
          2.        CAN_Write
          3.        CANprocessCANRxMsg
          4.        I2C_WriteReg
          5.        I2C_ReadReg
          6.        RS485_Send
          7.        RS485_Receive
        2. 3.2.2.2 Application Function List
          1.        Temp_Mux_Polling
          2.        BatteryDataUpdate_32s
          3.        BQ769x2_OTP_Programming
          4.        Check_Signal_Pattern
          5.        BMU_FET_Test
      3. 3.2.3 Software Workflow
    3. 3.3 Test Setup
    4. 3.4 Test Results
      1. 3.4.1 Cell Voltage Accuracy
      2. 3.4.2 Pack Current Accuracy
      3. 3.4.3 Auxiliary Power and System Current Consumption
      4. 3.4.4 Protection
      5. 3.4.5 Working Modes Transition
      6. 3.4.6 Thermistor Multiplexer
      7. 3.4.7 ESD Performance
      8. 3.4.8 Surge Immunity
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author
  12. 6Revision History

3.4.4 Protection

The design integrates a full set of battery cell protections, including: cell overvoltage, cell undervoltage, two levels of overcurrent discharge, overcurrent charge, discharge short circuit, and overtemperature and undertemperature protections. Furthermore, this design also monitors lots of system-level faults, including: cell open wire, host watch dog, charge and discharge MOSFETs faults, MOSFETs overtemperature, and so on. Some of the protections were tested in a TI lab.

TIDA-010247 Cell Overvoltage ProtectionFigure 3-11 Cell Overvoltage Protection
TIDA-010247 Overcurrent Discharge ProtectionFigure 3-13 Overcurrent Discharge Protection
TIDA-010247 Short-Circuit Discharge ProtectionFigure 3-15 Short-Circuit Discharge Protection
TIDA-010247 Cell Undervoltage ProtectionFigure 3-12 Cell Undervoltage Protection
TIDA-010247 Overcurrent Charge ProtectionFigure 3-14 Overcurrent Charge Protection
TIDA-010247 3.3V Short and HWD ProtectionsFigure 3-16 3.3V Short and HWD Protections

When 3.3V is shorted, the MCU is powered off and both BQ76972 devices detect host watchdog (HWD) protection after some delay. Since TIDA-010247 configures MCU wake up from entering lower power mode (no communication with the BQ76972 to save power) every 5s, observe a range of 5s to 10s delay with 10s HWD delay configurations.

TIDA-010247 120V On-PACK Port – Bottom AFE Maximum VoltageFigure 3-17 120V On-PACK Port – Bottom AFE Maximum Voltage
TIDA-010247 120V On-PACK Port – Top AFE Maximum VoltageFigure 3-18 120V On-PACK Port – Top AFE Maximum Voltage

The 120V on PACK port test is carried out with both CHG and DSG MOSFET off.