SLVS752D November   2007  – April 2026 TPS5420-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 
    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)
      7. 6.3.7  Internal Compensation
      8. 6.3.8  Voltage Feed Forward
      9. 6.3.9  Pulse-Width-Modulation (PWM) Control
      10. 6.3.10 Overcurrent Limiting
      11. 6.3.11 Overvoltage Protection (OVP)
      12. 6.3.12 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Minimum Input Voltage
      2. 6.4.2 ENA Control
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Application Circuits
        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
            3.         44
            4.         45
          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  Output Filter Component Selection
          9. 7.2.1.2.9  External Compensation Network
          10. 7.2.1.2.10 Advanced Information
            1. 7.2.1.2.10.1 Output Voltage Limitations
            2. 7.2.1.2.10.2 Internal Compensation Network
            3. 7.2.1.2.10.3 Thermal Calculations
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Additional Circuits
      3. 7.2.3 Circuit Using Ceramic Output Filter Capacitors
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 PCB 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

6.3.3 Enable (ENA) and Internal Slow Start

The ENA pin provides electrical on/off control of the regulator. Once the ENA pin voltage exceeds the threshold voltage, the regulator starts operation and the internal slow start begins to ramp. If the ENA pin voltage is pulled below the threshold voltage, the regulator stops switching and the internal slow start resets. Connecting the pin to ground or to any voltage less than 0.5V disables the regulator and activates the shutdown mode. The quiescent current of the TPS5420-Q1 in shutdown mode is typically 18μA.

ENA has an internal 1.5MΩ pullup resistor, allowing the user to float the ENA pin. If an application requires controlling the ENA pin, use open-drain or open-collector output logic to interface with the pin. Do not connect ENA pin with a resistor to ground. To limit the start-up inrush current, an internal slow start circuit is used to ramp up the reference voltage from 0 V to its final value linearly. The internal slow start time is 8 ms typically.