SLVS839H July   2008  – October 2023 TPS54331

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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 Switching Characteristics
    7. 6.7 Typical Characteristics
  8. 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  Voltage Reference (VREF)
      3. 7.3.3  Bootstrap Voltage (BOOT)
      4. 7.3.4  Enable and Adjustable Input Undervoltage Lockout (VIN UVLO)
      5. 7.3.5  Programmable Slow Start Using SS Pin
      6. 7.3.6  Error Amplifier
      7. 7.3.7  Slope Compensation
      8. 7.3.8  Current-Mode Compensation Design
      9. 7.3.9  Overcurrent Protection and Frequency Shift
      10. 7.3.10 Overvoltage Transient Protection
      11. 7.3.11 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Eco-mode
      2. 7.4.2 Operation With VIN < 3.5 V
      3. 7.4.3 Operation With EN Control
  9. 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  Custom Design with WEBENCH® Tools
        2. 8.2.2.2  Switching Frequency
        3. 8.2.2.3  Output Voltage Set-Point
        4. 8.2.2.4  Input Capacitors
        5. 8.2.2.5  Output Filter Components
          1. 8.2.2.5.1 Inductor Selection
        6. 8.2.2.6  Capacitor Selection
        7. 8.2.2.7  Compensation Components
        8. 8.2.2.8  Bootstrap Capacitor
        9. 8.2.2.9  Catch Diode
        10. 8.2.2.10 Output Voltage Limitations
        11. 8.2.2.11 Power Dissipation Estimate
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
      3. 8.4.3 Electromagnetic Interference (EMI) Considerations
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 Custom Design with WEBENCH® Tools
    2. 9.2 Support Resources
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Mechanical, Packaging, and Orderable Information

7.3.8 Current-Mode Compensation Design

To simplify design efforts using the TPS54331 device, the typical designs for common applications are listed in Table 7-1. For designs using ceramic output capacitors, proper derating of ceramic output capacitance is recommended when performing the stability analysis because the actual ceramic capacitance drops considerably from the nominal value when the applied voltage increases. See Section 8.2.2 for the detailed guidelines or use the WEBENCH software tool (www.TI.com/WEBENCH).

Table 7-1 Typical Designs (Refer to the Simplified Schematic)
VIN
(V)		VOUT
(V)		ƒSW
(kHz)		Lo
(μH)		Co RO1
(kΩ)		RO2
(kΩ)		C2
(pF)		C1
(pF)		R3
(kΩ)
1255706.8Ceramic 33 μF, ×2101.9139470049.9
123.35706.8Ceramic 47μF, ×2103.2447100029.4
121.85704.7Ceramic 100 μF108.0668560029.4
120.95703.3Ceramic 100 μF, ×21080.656560029.4
1255706.8Aluminum 330 μF, 160 mΩ101.916812029.4
123.35706.8Aluminum 470 μF, 160 mΩ103.248222010
121.85704.7SP 100 μF, 15 mΩ108.0668560029.4
120.95703.3SP 330 μF, 12 mΩ1080.6100120049.9