SLUSEG1A August   2021  – December 2021 TPS92519-Q1

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  Buck Converter Switching Operation
      2. 7.3.2  Switching Frequency and Adaptive On-Time Control
      3. 7.3.3  Minimum On-Time, Off-Time, and Inductor Ripple
      4. 7.3.4  Enable
      5. 7.3.5  LED Current Regulation and Error Amplifier
      6. 7.3.6  Start-up Sequence
      7. 7.3.7  Analog Dimming and Forced Continuous Conduction Mode
      8. 7.3.8  External PWM Dimming and Input Undervoltage Lockout (UVLO)
      9. 7.3.9  Shunt FET Dimming or Matrix Beam Application
      10. 7.3.10 Bias Supply
      11. 7.3.11 Bootstrap Supply
      12. 7.3.12 Faults and Diagnostics
      13. 7.3.13 Output Short Circuit Fault
      14. 7.3.14 Output Open Circuit Fault
      15. 7.3.15 Parallel Operation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power On Reset (POR)
      2. 7.4.2 Run Mode
      3. 7.4.3 Sleep Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1  Duty Cycle Consideration
      2. 8.1.2  Switching Frequency Selection
      3. 8.1.3  LED Current Set Point
      4. 8.1.4  Inductor Selection
      5. 8.1.5  Output Capacitor Selection
      6. 8.1.6  Input Capacitor Selection
      7. 8.1.7  Bootstrap Capacitor Selection
      8. 8.1.8  Compensation Capacitor Selection
      9. 8.1.9  Input Undervoltage Protection
      10. 8.1.10 CSN Protection Diode
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Calculating Duty Cycle
        2. 8.2.2.2 Calculating Minimum On-Time and Off-Time
        3. 8.2.2.3 Minimum Switching Frequency
        4. 8.2.2.4 LED Current Set Point
        5. 8.2.2.5 Inductor Selection
        6. 8.2.2.6 Output Capacitor Selection
        7. 8.2.2.7 Bootstrap Capacitor Selection
        8. 8.2.2.8 Compensation Capacitor Selection
        9. 8.2.2.9 PWM Dimming and Input Voltage Protection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Compact Layout for EMI Reduction
        1. 10.1.1.1 Ground Plane
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.5 Inductor Selection

The inductor is selected to meet the recommended 30% peak-to-peak inductor ripple specification:

Equation 28. GUID-20210402-CA0I-QMQR-JRCV-TJJZKP89MCF8-low.gif

The closest standard capacitor is 68 µH.

  • Lower inductor values increase the peak-to-peak inductor current, which minimizes size and cost at the expense of reduced efficiency and larger output capacitor.
  • Higher inductance values decrease the peak-to-peak inductor current, which increases efficiency but reduces the operating range based on minimum sense voltage ripple, ΔV(CSP-CSN) specification.