TNY278PN transformer.

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Dear all,
I have designed a 5v/1.7A (100Vac-300Vac) supply based on TNY278PN device. I have chosen EE16 for the core.I used PIXls designer on transformer design, from result on soft, i found Dmax(maximum duty cycle) was less than calculation.
I selected Vor=96Volts, from calculation, Vmin=122Volts. so,

actual Dmax=Vor/(Vor+(Vmin-Vds))=0.46, but on soft, its give out Dmax=0.39.

Could you give me some advice on it? Thinks in advance.

Attachment is soft result. please see.

Eric.