SLUS593J December   2003  – June 2022 TPS40054 , TPS40055 , TPS40057

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 Recommended Operating Conditions
    3. 6.3 Thermal Information
    4. 6.4 Electrical Characteristics
    5. 6.5 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 Setting the Switching Frequency (Programming the Clock Oscillator)
      2. 7.3.2 Programming The Ramp Generator Circuit
      3. 7.3.3 UVLO Operation
      4. 7.3.4 BP5 and BP10 Internal Voltage Regulators
      5. 7.3.5 Programming Soft Start
      6. 7.3.6 Programming Current Limit
      7. 7.3.7 Synchronizing to an External Supply
      8. 7.3.8 Loop Compensation
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Selecting the Inductor Value
      2. 8.1.2 Calculating the Output Capacitance
      3. 8.1.3 Calculating the Boost and BP10 Bypass Capacitor
      4. 8.1.4 DV-DT Induced Turn-On
      5. 8.1.5 High-Side MOSFET Power Dissipation
      6. 8.1.6 Synchronous Rectifier MOSFET Power Dissipation
      7. 8.1.7 TPS4005x Power Dissipation
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Calculate Maximum and Minimum Duty Cycles
        2. 8.2.2.2  Select Switching Frequency
        3. 8.2.2.3  Select ΔI
        4. 8.2.2.4  Calculate the High-Side MOSFET Power Losses
        5. 8.2.2.5  Calculate Synchronous Rectifier Losses
        6. 8.2.2.6  Calculate the Inductor Value
        7. 8.2.2.7  Set the Switching Frequency
        8. 8.2.2.8  Program the Ramp Generator Circuit
        9. 8.2.2.9  Calculate the Output Capacitance (CO)
        10. 8.2.2.10 Calculate the Soft-Start Capacitor (CSS/SD)
        11. 8.2.2.11 Calculate the Current Limit Resistor (RILIM)
        12. 8.2.2.12 Calculate Loop Compensation Values
        13. 8.2.2.13 Calculate the Boost and BP10V Bypass Capacitance
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 MOSFET Packaging
  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 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

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PWP|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.2.12 Calculate Loop Compensation Values

Calculate the DC modulator gain (AMOD) from Equation 12:

Equation 71. GUID-A63FD423-5CD5-4D80-A843-0347D059861C-low.gif

Calculate the output filter L-CO poles and CO ESR zeros from Equation 13 and Equation 14:

Equation 72. GUID-03A53042-D8E8-4A6D-8DAF-36A0099A0EAC-low.gif

and

Equation 73. GUID-EBC0B914-A82E-4C7C-A1EB-79E68A37367C-low.gif

Select the close-loop 0 dB crossover frequency, fC. For this example fC = 20 kHz.

Select the double zero location for the Type III compensation network at the output filter double pole at 4.93 kHz.

Select the double pole location for the Type III compensation network at the output capacitor ESR zero at 73.7 kHz.

The amplifier gain at the crossover frequency of 20 kHz is determined by the reciprocal of the modulator gain AMOD at the crossover frequency from Equation 22:

Equation 74. GUID-0FE7AAFB-5DB8-4CBA-B065-0706281A5790-low.gif

And also from Equation 22:

Equation 75. GUID-CB2DB409-A5A7-4B41-957C-C369676E13C0-low.gif

Choose R1 = 100 kΩ

The poles and zeros for a type III network are described in Equation 17 through Equation 21.

Equation 76. GUID-F933A2E8-DE8A-4336-9F6E-C44A88420FC8-low.gif
Equation 77. GUID-53262E0B-08F2-4EBF-8987-15B991D1D421-low.gif
Equation 78. GUID-C5E51BBC-86DB-4F0A-8C70-5A8976A8FEB1-low.gif
Equation 79. GUID-7A9F45B0-4C18-4391-A1FC-CEBB101067AE-low.gif
Equation 80. GUID-74311F3E-03EA-49A9-9B14-ECF30CEA9AFC-low.gif

Calculate the value of RBIAS from Equation 15 with R1 = 100 kΩ.

Equation 81. GUID-ECEC256E-E4C9-46CB-82AD-5EA3857C63B6-low.gif