SLVSIO1B March   2026  – April 2026 UCG28836 , UCG28846

PRODUCTION DATA  

  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 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Detailed Pin Descriptions
      1. 7.3.1  HV - High Voltage Input
      2. 7.3.2  SW - Switch Node
      3. 7.3.3  GND – Ground Return
      4. 7.3.4  FLT - External Overtemperature Fault
      5. 7.3.5  FB ­­– Feedback
      6. 7.3.6  TR - Turns Ratio
      7. 7.3.7  IPS - Peak Current, and Slew Rate
      8. 7.3.8  FCL - Frequency Clamp and Fault Response
      9. 7.3.9  CFX - CCM, Frequency Foldback and X-cap Discharge
      10. 7.3.10 VCC - Input Bias
    4. 7.4 Feature Description
      1. 7.4.1  Self Bias and Auxless Sensing
      2. 7.4.2  Control Law
        1. 7.4.2.1 Valley Switching
        2. 7.4.2.2 Frequency Foldback
        3. 7.4.2.3 Burst Mode
        4. 7.4.2.4 Continuous Conduction Mode (CCM)
      3. 7.4.3  GaN HEMT Switching Capability
      4. 7.4.4  Soft Start
      5. 7.4.5  Frequency Clamp
      6. 7.4.6  Frequency Dithering
      7. 7.4.7  Slew Rate Control
      8. 7.4.8  Transient Peak Power Capability
      9. 7.4.9  X-Cap Discharge
      10. 7.4.10 Fault Protections
        1. 7.4.10.1 Brownout Protection
        2. 7.4.10.2 Short-Circuit Protection
        3. 7.4.10.3 Output Overvoltage Protection
        4. 7.4.10.4 Overpower Protection (OPP, LPS)
        5. 7.4.10.5 Overtemperature Protection
        6. 7.4.10.6 Open FB Protection
        7. 7.4.10.7 Error Codes for Protections
  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 Input Bulk Capacitor
        2. 8.2.2.2 Transformer Primary Inductance and Turns Ratio
        3. 8.2.2.3 Output Capacitor
        4. 8.2.2.4 Selection Resistors
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 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
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.4.8 Transient Peak Power Capability

The UCG2883x/4x supports minimum of 2 times of transient peak output power capability for applications which require bursts of high power for short durations of time. The peak power is achieved without the need for oversizing the various components such as the transformer, power FETs, and so forth, and the same flyback design is usable for minimum of 2 times of the continuous output power rating for short durations. With this, a 65W flyback converter designed with UCG2883x/4x can deliver a minimum of 130W transient peak output power for a maximum of 120ms duration limited by the OPPH timer.

At high line input, the transient peak power delivery happens in DCM/QR modes of operation and is limited to maximum 120ms duration as per OPPH protection, as described in Section 7.4.10.4. At low line input, due to limitations in power delivery from DCM/QR modes, the continuous conduction mode (CCM) extends the operation to minimum 2 times of the nominal power rating. To limit the converter from excessive output power delivery at high line input, the CCM mode is disabled for input bulk capacitor voltage higher than 200V DC. The CCM mode of operation is described in Section 7.4.2.4. Peak power delivery in DCM/QR modes at higher than 140W for longer than 120ms triggers OPPH fault, as detailed in Section 7.4.10.4. A minimum of 2 times transient output power is supported, while maximum instantaneous transient output power in DCM/QR/CCM modes depends on the input bulk capacitor voltage and the power stage component values and is limited in time by the respective OPPH, and OPPL timers.