TIDT339 june   2023

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Required Equipment
    3. 1.3 Testing Conditions
    4. 1.4 Considerations
    5. 1.5 Dimensions
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs and Data
      1. 2.1.1 Efficiency Graph: Light Load Performance
      2. 2.1.2 Efficiency Graph: Available Output Power Versus Input Power
      3. 2.1.3 Efficiency Graph: Full Load Performance
      4. 2.1.4 Efficiency Data
        1.       17
        2.       18
        3.       19
    2. 2.2 Thermal Images
    3. 2.3 Static Output Voltage Variation versus Load
      1. 2.3.1 Light Load Range
      2. 2.3.2 Light to Full Load Range
    4. 2.4 EMI Measurement According to EN55022 Class-B Quasi-Peak Limits
  7. 3Waveforms
    1. 3.1 Switching on Q1 (VDS Voltage) at Full Load
    2. 3.2 Output Voltage Ripple
    3. 3.3 Load Transients
    4. 3.4 Start-Up and Shutdown Sequence
      1. 3.4.1 Start-Up Sequence
        1. 3.4.1.1 Load Current 0 A
        2. 3.4.1.2 Load Current 1.7 A
      2. 3.4.2 Shutdown Sequence

Description

This reference design is a quasi-resonant flyback power supply based on the UCC28730 primary side regulation (PSR) controller and UCC24650 (wake-up monitor). Using PSR topology eliminates the need of an optocoupler, increases reliability, and optimizes system cost. The design achieves less than 6-mW standby power (at 230 VAC) and over 85% efficiency at 25-W load.