TIDUDG1 July   2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 MIL-STD-1275E versus MIL-STD-1275D
      2. 2.2.2 Reverse Polarity Event
      3. 2.2.3 Voltage Spike Event
      4. 2.2.4 Voltage Spike Event: Component Selection
      5. 2.2.5 Voltage Surge Event
      6. 2.2.6 Voltage Surge Event: Component Selection
    3. 2.3 Highlighted Products
      1. 2.3.1 LM7480-Q1
      2. 2.3.2 LM5069
  8. 3Hardware, 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
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks

Description

The MIL-STD-1275E standard provides the latest characteristics for 28-V DC input power for utilization equipment in military vehicles. The standard characterizes three main events that occur during operation of a military vehicle, and any equipment connected to the 28-V main power supply must be protected against these three events. These events are: reverse polarity, voltage spike, and voltage surge event. To pass these events, do not operate the protection circuit during a reverse polarity event, and the output of the protection circuit should be nominal 28 V and maximum at 34 V throughout the duration of the spike and surge event. This reference design features a two-stage clamping circuit that can handle a maximum of 120-W output. By implementing a two-stage clamping circuit, the design helps reduce the overall cost of the BOM while minimizing its overall size.