SLVS751F November   2007  – April 2026 TPS5430-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information (DDA Package)
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Oscillator Frequency
      2. 6.3.2  Voltage Reference
      3. 6.3.3  Enable (ENA) and Internal Slow Start
      4. 6.3.4  Undervoltage Lockout (UVLO)
      5. 6.3.5  Boost Capacitor (BOOT)
      6. 6.3.6  Output Feedback (VSENSE) and Internal Compensation
      7. 6.3.7  Voltage Feed Forward
      8. 6.3.8  Pulse-Width Modulation (PWM) Control
      9. 6.3.9  Overcurrent Limiting
      10. 6.3.10 Overvoltage Protection (OVP)
      11. 6.3.11 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Operation near Minimum Input Voltage
      2. 6.4.2 Operation With ENA Control
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Application Circuit, 12V to 5V
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 7.2.1.2.2 Switching Frequency
          3. 7.2.1.2.3 Input Capacitors
          4. 7.2.1.2.4 Output Filter Components
            1. 7.2.1.2.4.1 Inductor Selection
            2. 7.2.1.2.4.2 Capacitor Selection
          5. 7.2.1.2.5 Output Voltage Setpoint
          6. 7.2.1.2.6 Boot Capacitor
          7. 7.2.1.2.7 Catch Diode
          8. 7.2.1.2.8 Advanced Information
            1. 7.2.1.2.8.1 Output Voltage Limitations
            2. 7.2.1.2.8.2 Internal Compensation Network
            3. 7.2.1.2.8.3 Thermal Calculations
        3. 7.2.1.3 Application Curves
      2. 7.2.2 9V to 21V Input to 5V Output Application Circuit
      3. 7.2.3 Circuit Using Ceramic Output Filter Capacitors
        1. 7.2.3.1 Output Filter Component Selection
        2. 7.2.3.2 External Compensation Network
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
7.2.1.2.7 Catch Diode

The TPS5430-Q1 is designed to operate using an external catch diode between PH and GND. The selected diode must meet the absolute maximum ratings for the application: reverse voltage must be higher than the maximum voltage at the PH pin, which is VIN(MAX) + 0.5V. Peak current must be greater than IOUT(MAX) plus one-half the peak to peak inductor current. Forward voltage drop must be small for higher efficiencies. Make sure to note that the catch diode conduction time is typically longer than the high-side FET on time, so attention paid to diode parameters can make a marked improvement in overall efficiency. Additionally, check that the device chosen is capable of dissipating the power losses. For this design, a Diodes, Inc. B340A is chosen, with a reverse voltage of 40V, forward current of 3A, and forward voltage drop of 0.5V.