DER-50
Set Top Box Design using TOP245R
April 20, 2005
Figure 13 – 18V Start-up Profile, 90VAC
Figure 14 –23V Start-up Profile, 90 VAC
5 V, 10 ms / div.
5 V, 10 ms / div.
10.3 Drain Voltage and Current Start-up Profile
Figure 15 - 90 VAC Input and Maximum Load.
Upper: IDRAIN, 0.5 A / div.
Figure 16 - 265 VAC Input and Maximum Load.
Upper: IDRAIN, 0.5 A / div.
Lower: VDRAIN, 100 V & 1 ms / div.
Lower: VDRAIN, 200 V & 1 ms / div.
10.4 Load Transient Response
In the figures shown below, signal averaging was used to better enable viewing the load
transient response. The oscilloscope was triggered using the load current step as a
trigger source. Since the output switching and line frequency occur essentially at random
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