SLUSCO8B November   2016  – June 2018 TPS54200 , TPS54201

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Excellent Deep Dimming in ADIM
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 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
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Fixed-Frequency PWM Control
      2. 8.3.2  Error Amplifier
      3. 8.3.3  Slope Compensation and Output Current
      4. 8.3.4  Input Undervoltage Lockout
      5. 8.3.5  Voltage Reference
      6. 8.3.6  Setting LED Current
      7. 8.3.7  Internal Soft Start
      8. 8.3.8  Bootstrap Voltage (BOOT)
      9. 8.3.9  Overcurrent Protection
        1. 8.3.9.1 High-Side MOSFET Overcurrent Protection
        2. 8.3.9.2 Low-Side MOSFET Overcurrent Protection
        3. 8.3.9.3 Low-Side MOSFET Reverse Overcurrent Protection
      10. 8.3.10 Fault Protection
        1. 8.3.10.1 LED-Open Protection
        2. 8.3.10.2 LED Short Protection
        3. 8.3.10.3 Sense-Resistor Short Protection
        4. 8.3.10.4 Sense-Resistor Open Protection
        5. 8.3.10.5 Overvoltage Protection
        6. 8.3.10.6 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Enable and Disable Device
      2. 8.4.2 Mode Detection
      3. 8.4.3 Analog Dimming Mode Operation
      4. 8.4.4 PWM Dimming-Mode Operation
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 TPS5420x 12-V Input, 1.5-A, 3-Piece IR LED Driver With Analog Dimming
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Inductor Selection
          2. 9.2.1.2.2 Input Capacitor Selection
          3. 9.2.1.2.3 Output Capacitor Selection
          4. 9.2.1.2.4 FB Pin RC Filter Selection
          5. 9.2.1.2.5 Sense Resistor Selection
        3. 9.2.1.3 Application Curves
      2. 9.2.2 TPS5420x 24-V Input, 1-A, 4-Piece WLED Driver With PWM Dimming
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Inductor Selection
          2. 9.2.2.2.2 Input Capacitor Selection
          3. 9.2.2.2.3 Output Capacitor Selection
          4. 9.2.2.2.4 FB Pin RC Filter Selection
          5. 9.2.2.2.5 Sense Resistor Selection
        3. 9.2.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.1 Overview

The TPS5420x device is a 1.5-A synchronous buck LED driver up to 28-V input. Current-mode operation provides fast transient response. The optimized internal compensation network minimizes the external component count and simplifies the control loop design.

The TPS5420x device has a fixed 600-kHz switching frequency for a good tradeoff between efficiency and size.

The integrated 150-mΩ high-side MOSFET and 70-mΩ low-side MOSFET allow for a high-efficiency LED driver with continuous output current up to 1.5 A.

The TPS5420x device supports deep dimming in both analog and PWM dimming modes. In analog dimming mode, the internal reference voltage is changed in proportion to the duty cycle of the PWM signal in the 1% to 100% range. In the PWM dimming mode, the LED turns on and off periodically according to the PWM duty cycle. For higher efficiency, the internal reference is halved to 100 mV.

Cycle-by-cycle current limit in the high-side MOSFET protects the converter in overload conditions and is enhanced by a low-side MOSFET freewheeling current limit which prevents current runaway. There is a low-side MOSFET sinking-current limit to prevent excessive reverse current.

For safety and protection, the TPS5420x includes LED-open and -short protection, sense-resistor-open and -short protection, and device thermal protection. The TPS54200 device implements shutdown-and-latch mode protection, whereas the TPS54201 device implements auto-retry mode protection.