SLUSG22 October   2025 UCC35131-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  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 Insulation Specifications
    6. 6.6 Electrical Characteristics
    7. 6.7 Safety-Related Certifications
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Pre-Production Samples Operating Limits
    3. 7.3 Functional Block Diagram
    4. 7.4 Feature Description
      1. 7.4.1 Power Stage Operation
        1. 7.4.1.1 VDD-COM Voltage Regulation
        2. 7.4.1.2 COM-VEE Voltage Regulation
      2. 7.4.2 Output Voltage Soft Start
      3. 7.4.3 ENA and Power-Good
      4. 7.4.4 Protection Functions
        1. 7.4.4.1 Input Undervoltage Lockout
        2. 7.4.4.2 Input Overvoltage Lockout
        3. 7.4.4.3 Output Undervoltage Protection
        4. 7.4.4.4 Output Overvoltage Protection
        5. 7.4.4.5 Over-Temperature Protection
        6. 7.4.4.6 BSW Pin Faults Protection
    5. 7.5 Device Functional Modes
  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 VDD-COM Voltage Regulation
        2. 8.2.2.2 COM-VEE Voltage Regulation and Single Output Configuration
    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
  10. 9 Device and Documentation Support
    1. 9.1 Third-Party Products Disclaimer
    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

7.4.4.4 Output Overvoltage Protection

The UCC35131-Q1 senses the output voltage through FBVDD and FBVEE pins to control the output voltage. To prevent the output voltage from getting too high, damaging the load or UCC35131-Q1 device, the UCC35131-Q1 is 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, the output voltages can exceed the regulation level. Based on the pin voltages on FBVDD and FBVEE, after the voltage exceeds the threshold, VVDD_OVP_R, or VVEE_OVP_R, the converter stops switching immediately.

In rare cases, the voltage divider can malfunction resulting in the wrong output voltage information. In turn, the control loop will regulate the output voltages at a wrong voltage level. For instances like this, the UCC35131-Q1 is also equipped with a fail-safe overvoltage protection. After the VDD-COM or COM-VEE voltage exceeds the overvoltage protection threshold VVDD_OVLOS_R or VVEE_OVLOS_R, the converter shuts down immediately. This fail-safe protection level is meant to protect UCC35131-Q1 rather than the load. The design must specify the voltage feedback divider normal operation at all conditions.