DER-37
16W Adapter using TOP245P
April 27, 2004
12.3 Drain Voltage and Current Start-up Profile
Figure 19 - 90 VAC Input and Maximum Load.
Upper: VDRAIN, 200 V & 1 ms / div.
Lower: IDRAIN, 0.5 A / div.
Figure 20 - 265 VAC Input and Maximum Load.
Upper: VDRAIN, 200 V & 1 ms / div.
Lower: IDRAIN, 0.5 A / div.
12.4 Load Transient Response (75% to 100% Load Step)
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
with respect to the load transient, contributions to the output ripple from these sources
will average out, leaving the contribution only from the load step response.
Figure 21 – Transient Response, 115 VAC, 75-100- Figure 22 – Transient Response, 230 VAC, 75-100-
75% Load Step.
75% Load Step
Waveform: Output Voltage
100 mV, 500 µs / div.
Waveform: Output Voltage
100 mV, 500uS / div.
Power Integrations
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