TIDUF43 August   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Terminology
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 TPS1213-Q1 45V, Low IQ, Automotive High-Side Switch Controller With Low-Power Mode and Adjustable Load Wakeup Trigger
      2. 2.3.2 INA296x-Q1 AEC-Q100, –5V to 110V, Bidirectional, 1.1MHz, 8V/μs, Ultra-Precise Current-Sense Amplifier
  9. 3System Design Theory
    1. 3.1 Low-Power Mode Considerations
    2. 3.2 Precharge Circuit Considerations
    3. 3.3 Short-Circuit Protection
    4. 3.4 LM74704-Q1 Enable
    5. 3.5 Headers
      1. 3.5.1 Headers for Configuring INA296B-Q1
      2. 3.5.2 Headers for Configuring TPS1213-Q1
    6. 3.6 Software Considerations
      1. 3.6.1 Fuse Channel Definition
      2. 3.6.2 Software Functions
    7. 3.7 Optional Output TVS Diode
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software
    3. 4.3 Test Setup
    4. 4.4 Test Results
      1. 4.4.1 State Transition
      2. 4.4.2 System IQ in Low-Power Mode
      3. 4.4.3 Precharge Test
      4. 4.4.4 Overcurrent Protection
      5. 4.4.5 PWM Overcurrent
      6. 4.4.6 Short-Circuit Protection
      7. 4.4.7 Thermal Testing
      8. 4.4.8 CISPR-25 Emissions Testing
        1. 4.4.8.1 Conducted Emissions Testing
        2. 4.4.8.2 Radiated Emissions Testing
        3. 4.4.8.3 Summary of Results
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
      3. 5.1.3 PCB Layout Recommendations
        1. 5.1.3.1 Layout Prints
      4. 5.1.4 Altium Project
      5. 5.1.5 Gerber Files
      6. 5.1.6 Assembly Drawings
    2. 5.2 Documentation Support
    3. 5.3 Support Resources
    4. 5.4 Trademarks
  12. 6About the Author

1 System Description

The TIDA-020065 automotive smart fuse design is targeted for power-distribution box and zone-control module systems. As vehicles shift from domain-based architecture to zone-based architecture, these systems aim to replace the standard melting fuse with a semiconductor design to allow for the following:

  1. Resettable fuses, which allow for optimized cable wiring as fuses no longer need to be in an easily-accesible location.
  2. Improved time-current characteristics across temperature, which allows for optimized harness cable diameter and reduced cost due to less variability between devices compared to standard melting fuses.

Nevertheless, replacing the melting fuse introduces the following challenges:

  1. Wire harness protection during overload and short-circuit events while avoiding tripping during peak load transient events
  2. Protect the FETs from uncontrolled inrush currents while charging load bulk capacitors
  3. Reducing semiconductor power consumption in key-off state for powered-at-all-times loads

The TIDA-020065 aims to demonstrate how these challenges can be addressed at a system-level for high-current loads. This design features the TPS1213-Q1 device for driving a main power path in the drive state, and a low power path for the key-off state. This design also features the INA296B3-Q1 device which is used to sense the load current so the MSPM0L1306-Q1 can run a software-based I2t algorithm to replicate fuse behavior.