SLUSDX7A September   2020  – October 2020 TPS51397A

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 PWM Operation and DCAP3 Control
      2. 7.3.2 Soft Start
      3. 7.3.3 Large Duty Operation
      4. 7.3.4 Power Good
      5. 7.3.5 Overcurrent Protection and Undervoltage Protection
      6. 7.3.6 Overvoltage Protection
      7. 7.3.7 UVLO Protection
      8. 7.3.8 Output Voltage Discharge
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Light Load Operation
      2. 7.4.2 Advanced Eco-mode Control
      3. 7.4.3 Out-of-Audio
      4. 7.4.4 Mode Selection
      5. 7.4.5 Standby Operation
  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 External Component Selection
          1. 8.2.2.1.1 Output Voltage Set Point
          2. 8.2.2.1.2 MODE Selection
          3. 8.2.2.1.3 Inductor Selection
          4. 8.2.2.1.4 Output Capacitor Selection
          5. 8.2.2.1.5 Input Capacitor Selection
      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 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

The inductor ripple current is filtered by the output capacitor. A higher inductor ripple current means the output capacitor should have a ripple current rating higher than the inductor ripple current. See Table 8-2 for recommended inductor values.

The RMS and peak currents through the inductor can be calculated using Equation 5 and Equation 6. It is important that the inductor is rated to handle these currents.

Equation 5. GUID-6C4CA405-9D84-4BAE-BBCD-29C6DEAD4C93-low.gif
Equation 6. GUID-A8DA7A0E-5892-4287-A20B-27C2E9D223BB-low.gif

Under transient and short-circuit conditions, the inductor current can increase up to the current limit of the device, so it is safe to choose an inductor with a saturation current higher than the peak current under current limit condition.