SLUSCV2 June 2017 TPS54308


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1Absolute Maximum Ratings
    2. 6.2ESD Ratings
    3. 6.3Recommended Operating Conditions
    4. 6.4Thermal Information
    5. 6.5Electrical Characteristics
    6. 6.6Timing Requirements
    7. 6.7Typical Characteristics
  7. Detailed Description
    1. 7.1Overview
    2. 7.2Functional Block Diagram
    3. 7.3Feature Description
      1. 7.3.1 Fixed-Frequency PWM Control
      2. 7.3.2 Force Continuous Conduction Mode (FCCM)
      3. 7.3.3 Error Amplifier
      4. 7.3.4 Slope Compensation and Output Current
      5. 7.3.5 Enable and Adjusting Undervoltage Lockout
      6. 7.3.6 Safe Startup into Pre-Biased Outputs
      7. 7.3.7 Voltage Reference
      8. 7.3.8 Adjusting Output Voltage
      9. 7.3.9 Internal Soft-Start
      10. 7.3.10Bootstrap Voltage (BOOT)
      11. 7.3.11Overcurrent Protection
        1. MOSFET Overcurrent Protection
        2. MOSFET Overcurrent Protection
      12. 7.3.12Output Overvoltage Protection (OVP)
      13. 7.3.13Thermal Shutdown
    4. 7.4Device Functional Modes
  8. Application and Implementation
    1. 8.1Application Information
    2. 8.2Typical Application
      1. 8.2.1TPS54308 8-V to 28-V Input, 5-V Output Converter
      2. 8.2.2Design Requirements
      3. 8.2.3Detailed Design Procedure
        1. Design With WEBENCH® Tools
        2. Capacitor Selection
        3. Capacitor Selection
        4. Voltage Set Point
        5. Lockout Set Point
        6. Filter Components
          1. Selection
          2. Capacitor Selection
          3. Capacitor
      4. 8.2.4Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1Layout Guidelines
    2. 10.2Layout Example
  11. 11Device and Documentation Support
    1. 11.1Device Support
      1. 11.1.1Development Support
        1. Design With WEBENCH® Tools
    2. 11.2Receiving Notification of Documentation Updates
    3. 11.3Community Resources
    4. 11.4Trademarks
    5. 11.5Electrostatic Discharge Caution
    6. 11.6Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information


  • 4.5-V to 28-V Wide Input Voltage Range
  • Integrated 85-mΩ and 40-mΩ MOSFETs for 3-A, Continuous Output Current
  • Low 2-μA Shutdown, 300-μA Quiescent Current
  • Internal 5-mS Soft-Start
  • Fixed 350-kHz Switching Frequency
  • Peak Current Mode Control
  • Internal Loop Compensation
  • Overcurrent Protection for Both MOSFETs with Hiccup Mode Protection
  • Over Voltage Protection
  • Thermal Shutdown
  • SOT-23 (6) Package
  • Create a Custom Design Using the TPS54308 With the WEBENCH® Power Designer


  • 12-V, 24-V Distributed Power-Bus Supply
  • Industry Application
    • White Goods
  • Consumer Application
    • Audio
    • STB, DTV
    • Printer


The TPS54308 is a 4.5-V to 28-V input voltage range, 3-A synchronous buck converter. The device includes two integrated switching FETs, internal loop compensation and 5-ms internal soft start to reduce component count.

By integrating the MOSFETs and employing the SOT-23 package, the TPS54308 achieves the high power density and offers a small footprint on the PCB.

The TPS54308 operates in force continous conduction mode (FCCM) during light load conditions, the switching frequency is maintained at an almost constant level over entire load range.

Cycle-by-cycle current limit in both high-side MOSFET protects the converter in an overload condition and is enhanced by a low-side MOSFET freewheeling current limit which prevents current runaway. Hiccup mode protection is triggered if the overcurrent condition has persisted for longer than the present time.

Device Information(1)

TPS54308SOT-23(6)1.60 mm × 2.90 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

TPS54308 alt_luscv2.gif

Efficiency vs Output Current

TPS54308 D019_sluscv2.gif