SLVSH40 November   2023 TPS92201 , TPS92201A

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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 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  Adaptive Off-time Control
      2. 7.3.2  Power Save Mode
      3. 7.3.3  Soft Startup
      4. 7.3.4  Low Dropout Operation
      5. 7.3.5  LED Current Setting
      6. 7.3.6  Voltage Reference
      7. 7.3.7  Switch Current Limit
      8. 7.3.8  Fault Behaviors
      9. 7.3.9  Under Voltage Lockout
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enabling/Disabling the Device
  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 Setting the Output Voltage
        3. 8.2.2.3 Output Filter Design
        4. 8.2.2.4 Inductor Selection
        5. 8.2.2.5 Input and Output Capacitor Selection
      3. 8.2.3 Application Performance 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 Thermal Considerations
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 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
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.4 Low Dropout Operation

The device offers a low input-to-output voltage differential by entering 100% switching duty cycle mode. In this mode, the high-side MOSFET switch is constantly turned on and the low-side MOSFET is switched off. The minimum input voltage to maintain output regulation, depending on the load current and output voltage, is calculated as:

Equation 1. VIN_MIN=VFB+ VF_IOUT+ IOUT x (RDS_ON+RL)

where

  • VFB is the feedback reference voltage, which is typically 100 mV
  • VF_IOUT is the LED forward voltage at output current
  • IOUT is the output current setting
  • RDS_ON is the high-side FET resistance when turning on
  • RL is the inductor ohmic resistance DCR