SLUS456G April   1999  – July 2025 UCC2808A-1 , UCC2808A-2 , UCC3808A-1 , UCC3808A-2

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Pin Descriptions
        1. 6.3.1.1 COMP
        2. 6.3.1.2 CS
        3. 6.3.1.3 FB
        4. 6.3.1.4 GND
        5. 6.3.1.5 OUTA and OUTB
        6. 6.3.1.6 RC
        7. 6.3.1.7 VDD
    4. 6.4 Device Functional Modes
      1. 6.4.1 VCC
      2. 6.4.2 Push-Pull or Half-Bridge Function
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.1.1 COMP

The COMP pin is the output of the error amplifier and the input of the PWM comparator. The error amplifier in the UCC3808 is a true low-output impedance, 2-MHz operational amplifier. As such, the COMP pin both sources and sinks current. However, the error amplifier is internally current limited, so the zero duty cycle is externally forced by pulling COMP to GND.

The UCC3808 family features built-in full cycle soft start. Soft start is implemented as a clamp on the maximum COMP voltage.