SLVSDQ7B October   2016  – July 2021 TPS57114C-Q1

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 ESD 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 and Output Current
      3. 7.3.3 Bootstrap Voltage (BOOT) and Low-Dropout Operation
        1. 7.3.3.1 Error Amplifier
      4. 7.3.4 Voltage Reference
    4. 7.4 Device Functional Modes
      1. 7.4.1  Adjusting the Output Voltage
      2. 7.4.2  Enable Functionality and Adjusting Undervoltage Lockout
      3. 7.4.3  Slow-Start or Tracking Pin
      4. 7.4.4  Sequencing
      5. 7.4.5  Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      6. 7.4.6  Overcurrent Protection
      7. 7.4.7  Frequency Shift
      8. 7.4.8  Reverse Overcurrent Protection
      9. 7.4.9  Synchronize Using The RT/CLK Pin
      10. 7.4.10 Power Good (PWRGD Pin)
      11. 7.4.11 Overvoltage Transient Protection
      12. 7.4.12 Thermal Shutdown
      13. 7.4.13 Small-Signal Model for Loop Response
      14. 7.4.14 Simple Small-Signal Model for Peak-Current Mode Control
      15. 7.4.15 Small-Signal Model for Frequency Compensation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Selecting the Switching Frequency
        2. 8.2.2.2 Output Inductor Selection
        3. 8.2.2.3 Output Capacitor
        4. 8.2.2.4 Input Capacitor
        5. 8.2.2.5 Slow-Start Capacitor
        6. 8.2.2.6 Bootstrap Capacitor Selection
        7. 8.2.2.7 Output-Voltage And Feedback-Resistor Selection
        8. 8.2.2.8 Compensation
        9. 8.2.2.9 Power-Dissipation Estimate
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.9 Power-Dissipation Estimate

The following formulas show how to estimate the IC power dissipation under continuous-conduction mode (CCM) operation. The power dissipation of the IC (PT) includes conduction loss (P(con)), dead-time loss (P(d)), switching loss (P(SW)), gate-drive loss (P(gd)), and supply-current loss (P(q)).

Equation 42. GUID-77B63DF6-755A-488E-B680-2723F3EBF678-low.gif
Equation 43. GUID-157FBA60-BC0F-464D-BF74-EB61FDAF14D6-low.gif
Equation 44. GUID-00D73B58-646F-4FE3-85C7-84E377F97C95-low.gif
Equation 45. GUID-28E27F59-C6CD-49FC-82BE-FA018355D3D0-low.gif
Equation 46. GUID-D0980563-BA02-45A7-8D2A-DF2FDCB9581E-low.gif

where:

  • IO is the output current (A)
  • rDS(on)(Temp) is the on-resistance of the high-side MOSFET with given temperature (Ω)
  • VI is the input voltage (V)
  • f(SW) is the switching frequency (Hz)

So

Equation 47. GUID-6E6FAC60-0315-4CE5-8459-4AE1FE25730E-low.gif

For a given TA,

Equation 48. GUID-552B6BD6-95D5-4F6E-878A-8A44E7CC6C7F-low.gif

For a given TJ(max) = 150°C

Equation 49. GUID-6BD55964-4764-432A-8D0D-606CA966ED6C-low.gif

where:

  • PT is the total device power dissipation (W)
  • TA is the ambient temperature (°C)
  • TJ is the junction temperature (°C)
  • RθJA is the thermal resistance of the package (°C/W)
  • TJ(max) is maximum junction temperature (°C)
  • TA(max) is maximum ambient temperature (°C)

There are additional power losses in the regulator circuit due to the inductor ac and dc losses and trace resistance that impact the overall efficiency of the regulator.