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

2.3.2 TPSI2140-Q1

The TPSI2140-Q1 is an isolated solid-state relay designed for high-voltage automotive and industrial applications. The TPSI2140-Q1 uses TI’s high-reliability capacitive isolation technology in combination with internal back-to-back MOSFETs to form a completely integrated design requiring no secondary-side power supply.

The primary side of the device is powered by only 9mA of input current and incorporates a fail-safe EN pin preventing any possibility of back-powering the VDD supply. In most applications, the VDD pin of the device must be connected to a system supply between 5V to 20V, and the EN pin of the device must be driven by a GPIO output with logic high between 2.1V to 20V. In other applications, the VDD and EN pins can be driven together directly from the system supply or from a GPIO output. All control configurations of the TPSI2140-Q1 do not require additional external components such as a resistor or low-side switch that are typically required in photo relay designs.

The secondary side consists of back-to-back MOSFETs with a standoff voltage of ±1.2kV from S1 to S2. The avalanche robustness of the TPSI2140-Q1 MOSFETs and thermally conscious package design allows robust support of system-level dielectric withstand testing (HiPot) and DC fast charger surge currents of up to 2mA without requiring any external components.