TIDUFE2 October   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Fault Detection and Protection
      2. 2.2.2 Theory of Operation - Parallel LDOs Using Op Amps
      3. 2.2.3 Theory of Operation - Parallel LDOs Using Ballast Resistors
    3. 2.3 Highlighted Products
      1. 2.3.1 TPS7B7702-Q1, Automotive, Dual-Channel Antenna Low Dropout (LDO) Regulator With Current Sense
      2. 2.3.2 OPAx388 Automotive, Precision, Zero-Drift, Zero-Crossover, True Rail-to-Rail, Input/Output Operational Amplifiers
      3. 2.3.3 LMV321A-Q1 Automotive Low-Voltage Rail-to-Rail Output Operational Amplifier
  9. 3Hardware, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Test Setup
    3. 3.3 Test Results - Parallel LDOs Using Op Amps
      1. 3.3.1 Short to Battery
      2. 3.3.2 Load Transient Response
      3. 3.3.3 Current Limit
      4. 3.3.4 Start-Up
      5. 3.3.5 Shutdown
      6. 3.3.6 Line Transient
      7. 3.3.7 PSRR
      8. 3.3.8 Thermal Performance
      9. 3.3.9 Thermal Limit Protection
    4. 3.4 Test Results - Parallel LDOs Using Ballast Resistors
      1. 3.4.1 Short to Battery
      2. 3.4.2 Load Transient Response
      3. 3.4.3 Current Limit
      4. 3.4.4 Start-Up
      5. 3.4.5 Line Transient
      6. 3.4.6 Thermal Performance
      7. 3.4.7 Thermal Limit Protection
    5. 3.5 Comparison of Results Between Parallel LDO Techniques
      1. 3.5.1 VLOAD vs ILOAD
      2. 3.5.2 PSRR
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 Layout Prints
    2. 4.2 Tools
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

2.2.1 Fault Detection and Protection

The TPS7B7702-Q1 includes both analog current sense and digital fault pins for full diagnostics of different fault conditions.

The current-sense voltage scale is selected based on the output-current range of interest. Figure 2-2 shows a recommended setting that allows for full diagnostics of each fault. Before the device goes into current-limit mode, the output current-sense voltage is linearly proportional to the actual load current. During a thermal-shutdown (TSD) and short-to-battery (STB) condition, the current-sense voltage is set to the fault voltage level that is specified in the electrical characteristics table of the TPS7B770x-Q1, Automotive, Single- and Dual-Channel Antenna LDO With Current Sense (TPS7B7702-Q1) data sheet.

TIDA-050096 Functionality of the Current Sense Output Figure 2-2 Functionality of the Current Sense Output