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Hello,
We using the UCC28070 for a 3.3kW charger.
In case of high duty (>85%) and low duty (<15%) the pulse width of phases A and B are not symmetrical.
Dont worry about the current signals. We use a coupled choke.
If the pulse width is asymmetrical the coupled choke can saturate.
We need symmetrical dutys at the phases.
Is the duty higher then 15% or lower then 85% the symmetrical of the phases are ok.
I switched the external circuit of phase A and B but the result was the same. The max. duty of phase A is arround 85%, but we set it with DMAX to 95%.
Is that a characteristic problem of the UCC28070?
Problems arround zero crossing:
Ch1: CSB, Ch2: CDA, Ch3: CSA, Ch4: CDB
Symmetrical dutys to compare:
With best regards
Ercan Aktas
