SLUSAE5G August   2011  – April 2021 TPS53355

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 (1)
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Infomation
    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 5-V LDO and VREG Start-Up
      2. 7.3.2 Adaptive On-Time D-CAP Control and Frequency Selection
      3. 7.3.3 Ramp Signal
      4. 7.3.4 Adaptive Zero Crossing
      5. 7.3.5 Power-Good
      6. 7.3.6 Current Sense, Overcurrent and Short Circuit Protection
      7. 7.3.7 Overvoltage and Undervoltage Protection
      8. 7.3.8 UVLO Protection
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enable, Soft Start, and Mode Selection
      2. 7.4.2 Auto-Skip Eco-mode™ Light Load Operation
      3. 7.4.3 Forced Continuous Conduction Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Small Signal Model
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application Circuit Diagram with Ceramic Output Capacitors
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 External Component Selection
          3. 8.2.1.2.3 External Component Selection Using All Ceramic Output Capacitors
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Application Circuit
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 External Component Selection
        3. 8.2.2.3 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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.3.7 Overvoltage and Undervoltage Protection

TPS53355 monitors a resistor divided feedback voltage to detect over and under voltage. When the feedback voltage becomes lower than 70% of the target voltage, the UVP comparator output goes high and an internal UVP delay counter begins counting. After 1ms, TPS53355 latches OFF both high-side and low-side MOSFETs drivers. The controller restarts after a hiccup delay (16 ms with 0.7 ms soft-start). This function is enabled 1.5-ms after the soft-start is completed.

When the feedback voltage becomes higher than 120% of the target voltage, the OVP comparator output goes high and the circuit latches OFF the high-side MOSFET driver and latches ON the low-side MOSFET driver. The output voltage decreases. If the output voltage reaches UV threshold, then both high-side MOSFET and low-side MOSFET driver will be OFF and the device restarts after a hiccup delay. If the OV condition remains, both high-side MOSFET and low-side MOSFET driver remains OFF until the OV condition is removed.