SLUS851D October   2008  – October 2014 TPS54231

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  5. 5 Revision History
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Fixed-Frequency PWM Control
      2. 8.3.2  Voltage Reference (Vref)
      3. 8.3.3  Bootstrap Voltage (BOOT)
      4. 8.3.4  Enable and Adjustable Input Undervoltage Lockout (VIN UVLO)
      5. 8.3.5  Programmable Slow Start Using SS Pin
      6. 8.3.6  Error Amplifier
      7. 8.3.7  Slope Compensation
      8. 8.3.8  Current-Mode Compensation Design
      9. 8.3.9  Overcurrent Protection and Frequency Shift
      10. 8.3.10 Overvoltage Transient Protection
      11. 8.3.11 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Eco-mode™
      2. 8.4.2 Operation With VIN < 3.5 V
      3. 8.4.3 Operation With EN Control
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Switching Frequency
        2. 9.2.2.2 Output Voltage Set Point
        3. 9.2.2.3 Input Capacitors
        4. 9.2.2.4 Output Filter Components
          1. 9.2.2.4.1 Inductor Selection
          2. 9.2.2.4.2 Capacitor Selection
        5. 9.2.2.5 Compensation Components
        6. 9.2.2.6 Bootstrap Capacitor
        7. 9.2.2.7 Catch Diode
        8. 9.2.2.8 Output Voltage Limitations
        9. 9.2.2.9 Power Dissipation Estimate
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Estimated Circuit Area
    4. 11.4 Electromagnetic Interference (EMI) Considerations
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

1 Features

  • 3.5- to 28-V Input Voltage Range
  • Adjustable Output Voltage Down to 0.8 V
  • Integrated 80-mΩ High-Side MOSFET Supports up to 2 A Continuous Output Current
  • High Efficiency at Light Loads with a Pulse Skipping Eco-mode™
  • Fixed 570-kHz Switching Frequency
  • Typical 1-μA Shutdown Quiescent Current
  • Adjustable Slow-Start Limits Inrush Currents
  • Programmable UVLO Threshold
  • Overvoltage Transient Protection
  • Cycle-by-Cycle Current Limit, Frequency Fold Back and Thermal Shutdown Protection
  • Available in Easy-to-Use SOIC8 Package
  • Supported by WEBENCH® Software Tool (www.TI.com/WEBENCH)

2 Applications

  • Consumer Applications such as Set-Top Boxes, CPE Equipment, LCD Displays, Peripherals, and Battery Chargers
  • Industrial and Car Audio Power Supplies
  • 5-V, 12-V and 24-V Distributed Power Systems

3 Description

The TPS54231 device is a 2-V, 2-A non-synchronous buck converter that integrates a low RDS(on) high-side MOSFET. To increase efficiency at light loads, a pulse skipping Eco-mode™ feature is automatically activated. Furthermore, the 1-μA shutdown supply current allows the device to be used in battery powered applications. Current mode control with internal slope compensation simplifies the external compensation calculations and reduces component count while allowing the use of ceramic output capacitors. A resistor divider programs the hysteresis of the input undervoltage lockout. An overvoltage transient protection circuit limits voltage overshoots during startup and transient conditions. A cycle-by-cycle current limit scheme, frequency fold back and thermal shutdown protect the device and the load in the event of an overload condition. The TPS54231 device is available in an 8-pin SOIC package that has been internally optimized to improve thermal performance.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TPS54231 SOIC (8) 4.90 mm × 3.90 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

4 Simplified Schematic

app_sch_lus851.gif

Efficiency

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