SLVSAA6B April   2010  – November 2014 TPS54240

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed Frequency PWM Control
      2. 7.3.2  Slope Compensation Output Current
      3. 7.3.3  Pulse Skip Eco-Mode
      4. 7.3.4  Low Dropout Operation and Bootstrap Voltage (BOOT)
      5. 7.3.5  Error Amplifier
      6. 7.3.6  Voltage Reference
      7. 7.3.7  Adjusting The Output Voltage
      8. 7.3.8  Enable And Adjusting Undervoltage Lockout
      9. 7.3.9  Slow-Start / Tracking Pin (SS/TR)
      10. 7.3.10 Overload Recovery Circuit
      11. 7.3.11 Sequencing
      12. 7.3.12 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      13. 7.3.13 Overcurrent Protection and Frequency Shift
      14. 7.3.14 Selecting the Switching Frequency
      15. 7.3.15 How to Interface to RT/CLK Pin
      16. 7.3.16 Powergood (PWRGD Pin)
      17. 7.3.17 Overvoltage Transient Protection
      18. 7.3.18 Thermal Shutdown
      19. 7.3.19 Small Signal Model for Loop Response
      20. 7.3.20 Simple Small Signal Model for Peak Current Mode Control
      21. 7.3.21 Small Signal Model for Frequency Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation Near Minimum VIN (V(VIN) = < 3.5 V)
      2. 7.4.2 Operation With EN Control
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 TPS54240 3.3-V Output Design
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Selecting the Switching Frequency
          2. 8.2.1.2.2  Output Inductor Selection (LO)
          3. 8.2.1.2.3  Output Capacitor
          4. 8.2.1.2.4  Catch Diode
          5. 8.2.1.2.5  Input Capacitor
          6. 8.2.1.2.6  Slow-Start Capacitor
          7. 8.2.1.2.7  Bootstrap Capacitor Selection
          8. 8.2.1.2.8  Undervoltage Lock Out Set Point
          9. 8.2.1.2.9  Output Voltage And Feedback Resistors Selection
          10. 8.2.1.2.10 Compensation
          11. 8.2.1.2.11 Discontinuous Mode And Eco-Mode Boundary
          12. 8.2.1.2.12 Power Dissipation Estimate
        3. 8.2.1.3 Application Curves
      2. 8.2.2 TPS54240 Inverting Power Supply
      3. 8.2.3 TPS54240 Split Rail Power Supply
      4. 8.2.4 12-V To 3.8-V GSM Power Supply
      5. 8.2.5 24-V to 4.2-V GSM Power Supply
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Estimated Circuit Area
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • 3.5-V to 42-V Input Voltage Range
  • 200-mΩ High-Side MOSFET
  • High Efficiency at Light Loads With a Pulse Skipping Eco-Mode™
  • 138-μA Operating Quiescent Current
  • 1.3-μA Shutdown Current
  • 100-kHz to 2.5-MHz Switching Frequency
  • Synchronizes to External Clock
  • Adjustable Slow Start and Sequencing
  • UV and OV Power Good Output
  • Adjustable UVLO Voltage and Hysteresis
  • 0.8-V Internal Voltage Reference
  • 10-Pin HVSSOP and 10-Pin 3-mm x 3-mm VSON Packages with PowerPAD™
  • Supported by WEBENCH® Software Tool

2 Applications

  • 12-V and 24-V Industrial and Commercial Low-Power Systems
  • GSM, GPRS Modules in Fleet Management,
    eMeters, and Security Systems

3 Description

The TPS54240 device is a 42-V, 2.5-A, step-down regulator with an integrated high-side MOSFET. Current mode control provides simple external compensation and flexible component selection. A low-ripple, pulse skip mode reduces the no load, regulated output supply current to 138 μA. Using the enable pin, shutdown supply current is reduced to 1.3 μA, when the enable pin is low.

Undervoltage lockout is internally set at 2.5 V, but it can be increased using the enable pin. The output voltage startup ramp is controlled by the slow-start pin that can also be configured for sequencing and tracking. An open-drain power good signal indicates the output is within 94% to 107% of its nominal voltage.

A wide switching frequency range allows efficiency and optimization of external component size. Frequency foldback and thermal shutdown protects the part during an overload condition.

The TPS54240 is available in 10-pin, thermally-enhanced HVSSOP and 10-pin 3-mm x 3-mm PowerPAD package.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TPS54240 HVSSOP (10) 3.00 mm x 3.00 mm
VSON (10)
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

sim_sch_lvsaa6.gif

Efficiency vs Load Current

eff_il2_lvsa86.gif