TIDT225 March   2021

 

  1. 1Description
  2. 2Test Prerequisites
    1. 2.1 Voltage and Current Requirements
    2. 2.2 Required Equipment
  3. 3Testing and Results
    1. 3.1 Thermal Images
    2. 3.2 Efficiency and Power Dissipation Graphs
    3. 3.3 Efficiency and Power Dissipation Data
    4. 3.4 Cross Regulation
    5. 3.5 Loop Gain
  4. 4Waveforms
    1. 4.1 Start-up
    2. 4.2 Switching Waveforms
    3. 4.3 Output Voltage Ripple
    4. 4.4 Load Transients

4.1 Start-up

Start-up behavior is shown in the following figures.

GUID-20210219-CA0I-3GTT-VF6X-RDP9MXZDVG6Q-low.jpg
All outputs are at max loads
Figure 4-1 Start-up Sequence for +18V1 (Blue) and –5.1V1 (Green) With Vin = 12 V (Red)
GUID-20210219-CA0I-QQFF-NPLG-GJWHMNVBGHVH-low.jpg
All outputs are unloaded
Figure 4-2 Start-up Sequence for +18V1 (Blue) and –5.1V1 (Green) With Vin = 12 V (Red)
GUID-20210219-CA0I-CSB2-0NZS-ZF6RJMMLGM3F-low.jpg
All outputs are at max loads
Noise on isolated outputs V2, V3, or V4 can be reduced by adding a common-mode capacitor, similar to C26, on each output
Figure 4-3 Start-up Sequence for +18V4 (Blue) and –5.1V4 (Green) With Vin = 12 V (Red)
GUID-20210219-CA0I-JFNL-59WH-WBKGFDTMVG3R-low.jpg
All outputs are unloaded
Figure 4-4 Start-up Sequence for +18V4 (Blue) and –5.1V4 (Green) With Vin = 12 V (Red)