SLVSF07F July   2021  – August 2024 TPS7H5001-SP , TPS7H5002-SP , TPS7H5003-SP , TPS7H5004-SP

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Device Options
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics: All Devices
    6. 7.6  Electrical Characteristics: TPS7H5001-SP
    7. 7.7  Electrical Characteristics: TPS7H5002-SP
    8. 7.8  Electrical Characteristics: TPS7H5003-SP
    9. 7.9  Electrical Characteristics: TPS7H5004-SP
    10. 7.10 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  VIN and VLDO
      2. 8.3.2  Start-Up
      3. 8.3.3  Enable and Undervoltage Lockout (UVLO)
      4. 8.3.4  Voltage Reference
      5. 8.3.5  Error Amplifier
      6. 8.3.6  Output Voltage Programming
      7. 8.3.7  Soft Start (SS)
      8. 8.3.8  Switching Frequency and External Synchronization
        1. 8.3.8.1 Internal Oscillator Mode
        2. 8.3.8.2 External Synchronization Mode
        3. 8.3.8.3 Primary-Secondary Mode
      9. 8.3.9  Primary Switching Outputs (OUTA/OUTB)
      10. 8.3.10 Synchronous Rectifier Outputs (SRA and SRB)
      11. 8.3.11 Dead Time and Leading Edge Blank Time Programmability (PS, SP, and LEB)
      12. 8.3.12 Pulse Skipping
      13. 8.3.13 Duty Cycle Programmability
      14. 8.3.14 Current Sense and PWM Generation (CS_ILIM)
      15. 8.3.15 Hiccup Mode Operation (HICC)
      16. 8.3.16 External Fault Protection (FAULT)
      17. 8.3.17 Slope Compensation (RSC)
      18. 8.3.18 Frequency Compensation
      19. 8.3.19 Thermal Shutdown
    4. 8.4 Device Functional Modes
  10. 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 Programming Resistors
        3. 9.2.2.3  Dead Time
        4. 9.2.2.4  Leading Edge Blank Time
        5. 9.2.2.5  Soft-Start Capacitor
        6. 9.2.2.6  Transformer
        7. 9.2.2.7  Main Switching FETs
        8. 9.2.2.8  Synchronous Rectificier FETs
        9. 9.2.2.9  RCD Clamp
        10. 9.2.2.10 Output Inductor
        11. 9.2.2.11 Output Capacitance and Filter
        12. 9.2.2.12 Sense Resistor
        13. 9.2.2.13 Hiccup Capacitor
        14. 9.2.2.14 Frequency Compensation Components
        15. 9.2.2.15 Slope Compensation Resistor
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

9.2.2.14 Frequency Compensation Components

For this design, Type 2A compensation was used. With a target crossover frequency of 10 kHz, the guidelines shown in Section 8.3.18 are used here to determine the compensation values needed for the compensation network. The power stage transconductance is first needed in order to calculate the frequency compensation component values.

Equation 79. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 80. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP

With the power stage transconductance calculated as 16.2 A/V, the values of the external components needed at the COMP pin can be resolved.

Equation 81. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 82. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 83. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 84. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP

For the output capacitance 7 × 330-μF polymer tantalum capacitors were used to meet the 2.3-mF value that was needed for the design. At the selected switching frequency and output voltage, each of these capacitors had an ESR of roughly 6 mΩ. As such, the equivalent ESR used to determine the frequency of the ESR zero in the frequency response is equivalent the parallel resistance of these seven capacitors, which is 0.86 mΩ. The ESR zero frequency is then used in the calculation of CHF.

Equation 85. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 86. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 87. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP
Equation 88. TPS7H5001-SP TPS7H5002-SP TPS7H5003-SP TPS7H5004-SP

The values of RCOMP, CCOMP, and CHF selected were 40.2 kΩ, 15 nF, and 47 pF, respectively. Note that like many other aspects of the design, the frequency compensation is often tuned during testing in order to obtain the best possible performance.