TIDUF88 October   2024

 

  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 Accuracy of Bus Voltage Measuring
      2. 2.2.2 Shunt Current Measuring
      3. 2.2.3 Insulation Impedance Monitor
    3. 2.3 Highlighted Products
      1. 2.3.1 BQ79731-Q1
      2. 2.3.2 TPSI2140-Q1
      3. 2.3.3 ISO7841
      4. 2.3.4 SN6507
      5. 2.3.5 TPS7B6950
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Bus Voltage Accuracy
      2. 3.3.2 Current Sensing Accuracy
      3. 3.3.3 Insulation Impedance Accuracy
  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

2.3.1 BQ79731-Q1

The device can be used to measure divided down high-voltage nodes in a battery system. The device can measure voltage across fuses and contactors. The device can check isolation voltage in a battery junction box (BJB) system. The device has two integrated current sense (BQ79731-Q1) paths supporting low-side shunt resistors. The coulomb counting (BQ79731-Q1) function is available for accurate SOC calculation. There are 15 GPIOs and auxiliary inputs that can be used for high-voltage measurements, thermistor measurements, and driving relays. There are four software outputs that can be used to drive metal-oxide semiconductor field-effect transistor (MOSFET) switches in the measurement path. The device can function as an SPI hub and interface with up to eight separate SPI devices or groups. Overcurrent protection response can be achieved autonomously using hardware pins for fast protection in dangerous overcurrent events. The isolated bidirectional daisy chain ports support both capacitor and transformer-based isolation. The device can also communicate with the MCU over SPI.