Other Parts Discussed in Thread: UCC256302, , UCC28056
Ben-san,
UCC25630-1EVM-291 (IC changed to UCC256302) LLC load transient response evaluation
With the combination of PFC and LLC (input AC100 V, output DC 12 V 10 A condition),
LLC load transient response evaluation of load sudden change rate 0 ⇔ 100%,
duty 50%, 10 Hz in CC mode and CR mode was done.
As a result, immediately after the LLC output suddenly changes from 0% load to 100% load,
the output was stopped.
I think this is malfunction of LLC evaluation board.
So the output transient response test was performed again only on the LLC evaluation board.
As a result, similar trouble symptoms occurred again, so I show the test conditions and
indicates a defect observed waveform.
When evaluating with only LLC, the problem of load fluctuation occurred in case of the input voltage
is higher than DC 390 V.
When I test it with PFC, I think that this symptom is likely to occur at the timing at the voltage rises
due to load fluctuation of PFC output.
This problem is caused by whether there is a problem in the circuit setting of the LLC evaluation board
or due to limit of IC ability.
please check the attached pdf waveform.
LLC load transient response evaluation.pdf
What do you think about?
