SLUSE80C September   2021  – December 2022 UCC14240-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  Power Ratings
    6. 6.6  Insulation Specifications
    7. 6.7  Safety-Related Certifications
    8. 6.8  Electrical Characteristics
    9. 6.9  Safety Limiting Values
    10. 6.10 Insulation Characteristics
    11. 6.11 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 Power Stage Operation
        1. 7.3.1.1 VDD-VEE Voltage Regulation
        2. 7.3.1.2 COM-VEE Voltage Regulation
        3. 7.3.1.3 Power Handling Capability
      2. 7.3.2 Output Voltage Soft Start
      3. 7.3.3 ENA and PG
      4. 7.3.4 Protection Functions
        1. 7.3.4.1 Input Undervoltage Lockout
        2. 7.3.4.2 Input Overvoltage Lockout
        3. 7.3.4.3 Output Overvoltage Protection
        4. 7.3.4.4 Overpower Protection
          1. 7.3.4.4.1 Output Undervoltage Protection
        5. 7.3.4.5 Overtemperature Protection
    4. 7.4 Device Functional Modes
  8. 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 Capacitor Selection
        2. 8.2.2.2 RLIM Resistor Selection
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

7.3.4.3 Output Overvoltage Protection

The UCC14240-Q1 devices sense the output voltage through FBVDD and FBVEE pins to control the output voltage. To prevent the output voltage becomes too high, damages the load or UCC14240-Q1 device itself, the UCC14240-Q1 devices are equipped with the output overvoltage protection. There are two levels of overvoltage protection, based on the feedback pin voltage, and the output voltage.

During the normal operation, because of load transient, or load unbalancing between two outputs, the output voltages can exceed its regulation level. Based on the pin voltages on FBVDD and FBVEE, after the voltage exceeds the threshold, VVDD_OVP_RISE, or VVEE_OVP_RISE (10% above the target regulation voltage), the converter stops switching immediately.

In rare cases, the voltage divider becomes malfunction and gives the wrong output voltage information. In turn, the control loop can regulate the output voltages at a wrong voltage level. The UCC14240-Q1 device is also equipped with a fail-safe overvoltage protection. After the VDD-VEE voltage becomes higher than the overvoltage protection threshold VVDD_OVLOS_RISE, the converter shuts down immediately. This fail-safe protection level is set at 31 V. It is meant to protect UCC14240-Q1 devices, instead of the load. The design must ensure the voltage feedback divider normal operation at all conditions.

The output overvoltage protections have the latch-off response.