TIDUC65 April   2022 TPSI3050 , TPSI3050-Q1 , TPSI3052 , TPSI3052-Q1

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
    3. 2.3 Design Considerations
      1. 2.3.1 Overcurrent Protection (OCP)
        1. 2.3.1.1 Immediate Overcurrent Protection
        2. 2.3.1.2 Adjustable Delay Overcurrent Protection
      2. 2.3.2 Overtemperature Protection (OTP)
        1. 2.3.2.1 TMP392
        2. 2.3.2.2 ISO7310
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 Altium Project
      4. 4.1.4 Assembly Drawings
      5. 4.1.5 Gerber Files
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author

1 System Description

This reference design shows how to achieve a solid state relay solution with overcurrent and overtemperature protection, using the reinforced isolated switch driver TPSI3050-Q1. Protecting sensitive circuit components from overstress conditions increases the lifetime of the overall system and reliability. The risks of not implementing a well-designed protection scheme can be catastrophic for the circuit in the presence of an overcurrent event. This reference design proposes a two-level overcurrent and overtemperature protection scheme.

For the overcurrent protection, a two-level protection scheme is designed such that when the current load is greater than 2 A but less than 5 A, the circuit logic provides a delay of at least 100 ms before the load is disconnected. This delay can be used to allow for momentary inrush currents in the case of a highly capacitive load. When the current load exceeds the the max limit of 5 A, the load is immediately disconnected. The immediate load disconnect is used in case of a dangerous short circuit.

In the case of the overtemperature protection, when the circuit is within the lower limit between 60 °C to 90 °C, a visual warning is shown by a red LED which represents a hot surface. When the temperature is above the upper limit 90 °C, the load is disconnected.

There are several advantages of using the TPSI3050-Q1 as an isolated switch driver. TPSI3050-Q1 eliminates the need for isolated bias and isolated supply by generating a well-regulated 10 V gate drive voltage and a 5 V supply to power the auxiliary circuit. In addition, TPSI3050-Q1 can supply up to 50 mW to auxiliary circuitry. The TPSI3050-Q1 offers 5 kVRMS reinforced isolation and AEC-Q100 qualification for automotive applications while the TPSI3050 offers 3 kVRMS basic isolation for industrial applications.