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

7.2.3.1 Output Filter Component Selection

Using Equation 10, the minimum inductor value is 12μH. A value of 15μH is chosen for this design.

When using ceramic output filter capacitors, the recommended LC resonant frequency must be no more than 7kHz. Because the output inductor is already selected at 15μH, this selection limits the minimum output capacitor value to:

Equation 22. TPS5430-Q1

The minimum capacitor value is calculated to be 34μF. For this circuit a larger value of capacitor yields better transient response. A single 100μF output capacitor is used for C3. Make sure to note that the actual capacitance of ceramic capacitors decreases with applied voltage. In this example, the output voltage is set to 3.3V, minimizing this effect.