SLVSDV6C November   2017  – November 2019 TPS62821 , TPS62822 , TPS62823

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic space space space space
      2.      Efficiency vs Output Current space
  4. 4 Revision History
  5. 5 Device Comparison Table
  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 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 Enable / Shutdown and Output Discharge
      2. 8.3.2 Soft-Start
      3. 8.3.3 Power Good (PG)
      4. 8.3.4 Undervoltage Lockout (UVLO)
      5. 8.3.5 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode (PSM) Operation
      3. 8.4.3 Minimum Duty Cycle and 100% Mode Operation
      4. 8.4.4 Current Limit and Short Circuit Protection
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Custom Design With WEBENCH® Tools
        2. 9.2.2.2 Setting the Adjustable Output Voltage
        3. 9.2.2.3 Feed-forward Capacitor Selection
        4. 9.2.2.4 Output Filter Selection
        5. 9.2.2.5 Inductor Selection
        6. 9.2.2.6 Output Capacitor Selection
        7. 9.2.2.7 Input Capacitor Selection
      3. 9.2.3 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 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

8.4.4 Current Limit and Short Circuit Protection

The peak switch current of TPS6282x is internally limited, cycle by cycle, to a maximum dc value as specified in Electrical Characteristics. This prevents the device from drawing excessive current in case of externally caused over current or short circuit condition. Due to an internal propagation delay of about 60ns, the actual ac peak current can exceed the static current limit during that time.

If the current limit threshold is reached, the device delivers its maximum output current. Detecting this condition for 32 switching cycles (about 13µs), the device turns off the high-side MOSFET for about 100µs which allows the inductor current to decrease through the low-side MOSFET's body diode and then restarts again with a soft start cycle. As long as the overload condition is present, the device hiccups that way, limiting the output power.