SLUSES9 July   2022 TPS563300

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 Peak Current Mode
      2. 7.3.2  Pulse Frequency Modulation
      3. 7.3.3  Voltage Reference
      4. 7.3.4  Output Voltage Setting
      5. 7.3.5  Enable and Adjusting Undervoltage Lockout
      6. 7.3.6  Minimum On Time, Minimum Off Time, and Frequency Foldback
      7. 7.3.7  Frequency Spread Spectrum
      8. 7.3.8  Overvoltage Protection
      9. 7.3.9  Overcurrent and Undervoltage Protection
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Modes Overview
      2. 7.4.2 Heavy Load Operation
      3. 7.4.3 Light-Load Operation
      4. 7.4.4 Dropout Operation
      5. 7.4.5 Minimum On-Time Operation
      6. 7.4.6 Shutdown Mode
  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 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Resistors Selection
        3. 8.2.2.3 Bootstrap Capacitor Selection
        4. 8.2.2.4 Undervoltage Lockout Set Point
        5. 8.2.2.5 Output Inductor Selection
        6. 8.2.2.6 Output Capacitor Selection
        7. 8.2.2.7 Input Capacitor Selection
        8. 8.2.2.8 Feedforward Capacitor CFF Selection
        9. 8.2.2.9 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
        1. 9.1.2.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.7 Input Capacitor Selection

The TPS563300 device requires an input decoupling capacitor and, depending on the application, a bulk input capacitor. The typical recommended value for the decoupling capacitor is 10 μF, and an additional 0.1-µF capacitor from the VIN pin to ground is recommended to provide high frequency filtering.

The value of a ceramic capacitor varies significantly over temperature and the amount of DC bias applied to the capacitor. X5R and X7R ceramic dielectrics are recommended because they have a high capacitance-to-volume ratio and are fairly stable over temperature. The capacitor must also be selected with the DC bias taken into account. The effective capacitance value decreases as the DC bias increases.

The capacitor voltage rating needs to be greater than the maximum input voltage. The capacitor must also have a ripple current rating greater than the maximum input current ripple of the TPS563300. The input ripple current can be calculated using Equation 20.

Equation 20. GUID-E9F0E4CA-5FC5-45F1-B369-AFEB9E145C83-low.gif

For this example design, two TDK CGA5L1X7R1H106K160AC (10-μF, 50-V, 1206, X7R) capacitors have been selected. The effective capacitance under input voltage of 24 V for each one is 3.45 μF. The input capacitance value determines the input ripple voltage of the converter. The input voltage ripple can be calculated using Equation 21. Using the design example values, IOUT_MAX = 3 A, CIN_EFF = 2 × 3.45 = 6.9 μF, and fSW = 500 kHz, yields an input voltage ripple of 222 mV and a RMS input ripple current of 1.22 A.

Equation 21. GUID-CE7EA97D-D384-4C82-B5F5-91BC6291D20F-low.gif

where

  • RESR_MAX is the maximum series resistance of the input capacitor (approximately 1.5 mΩ of two capacitors in paralleled).