Dynamic Characteristics - Delta Electronics Delphi S48SS Series Evaluation Manual

8.2.3 Output Ripple
Output Ripple is defined as the periodic AC component at the DC/DC converters
output voltage. The output ripple is measured in Peak to Peak and RMS values, both
done with a specific bandwidth.
Test
1) Turn on the fan.
2) Set the enable switch SW1 to the appropriate logic enable position.
3) Adjust the input voltage and output load to the desired operating point (S48SS
only).
4) Adjust Channel 2 on the oscilloscope to be AC coupled @ 2uS / Div and 50mV/Div
to use the 20 MHz bandwidth of the scope.
5) The output ripple of the DC/DC converter is measured at full load operating power.

8.3 Dynamic Characteristics

8.3.1 Output Voltage Deviation
Output Voltage Deviation is defined as the response of the converter to a sudden step
change in the output load current. The output voltage deviation is characterized by two
important parameters: Maximum Output Voltage Deviation and Response Time, which
is the length of time that the output voltage takes to return to 1% of its specified value
(please refer to the datasheet for the detailed specification).
Test -S48SS & S48SR
1) Turn on the fan.
2) Set the enable switch SW1 to the appropriate logic enable position (S48SS only).
3) Adjust the input voltage to the desired operating point.
4) Set Channel 2 on the oscilloscope to be AC coupled and to 50mV/Div and
5mS/Div. Set the trigger to auto and adjust the trigger point for a negative going
pulse.
5) Set the Electronic Load in dynamic mode and set it for the desired load transient.
6) Measure the positive Peak or negative Peak deviation and response time of the
output voltage during the load transient.
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