TIDT355 October   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 Dimensions
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Efficiency Data
    3. 2.3 Thermal Images
  7. 3Waveforms
    1. 3.1 Switching
    2. 3.2 Output Voltage Ripple
    3. 3.3 Load Transients
    4. 3.4 Start-Up and Power-Down Sequence
    5. 3.5 Overcurrent Protection
    6. 3.6 Short-Circuit Protection

2.3 Thermal Images

Table 2-2 shows the thermal images at the four voltages. All images were captured with 25ºC ambient, after a 30-minute warm up and with an airflow of 200 LFM.

Table 2-2 Thermal Image Data
Temperature (°C)
600 VIN 800 VIN 1000 VIN 1500 VIN
High-side switch Q1 46.3 47.3 49.4 55.4
Low-side switch Q2 42.4 43.5 43.2 47.3
Transformer 52.2 winding 52.4 Core 55.2 winding 54.3 core 59.2 winding 55.2 Core 62.3 winding, 58.2 Core
Secondary diode (24 V) 50.5 52.1 53.1 55.2
Secondary diode (15 V) 47.2 48.5 49.3 53.2
Secondary diode (–15 V) 41.4 42.3 44.6 45.6
Secondary diode (8 V) 46.2 47.2 48.5 50.3
UCC28740 34.5. 36.1 39.2 41.2
GUID-20230922-SS0I-T8F3-HB0T-F21XNTDHVT5V-low.pngFigure 2-2 Thermal Image at 1500 VIN Full Load
GUID-20230922-SS0I-4WVN-JKDR-PLXMMXJD5MPM-low.pngFigure 2-4 Thermal Image at 800 VIN Full Load
GUID-20230922-SS0I-8GS2-WC7K-B9PX1RKWPPJG-low.pngFigure 2-3 Thermal Image at 1000 VIN Full Load
GUID-20230922-SS0I-DM0T-PXWS-DRG5W3KMGZLL-low.pngFigure 2-5 Thermal Image at 600 VIN Full Load