UCC28730-Q1: Rs1 setting at wide input voltage range

Part Number:UCC28730-Q1

Hi,

We got a question from the customer about UCC28730-Q1.
Could you help us?

[Question]
They are considering using the IC at DC30V to DC600V input voltage range.

So they are concerned about the setting of Rs1. They assume that Ivsl has to exceed 225uA at all over input voltage range. However, at high input voltage condition, Ivsl exceeds the maximum absolute rating due to the auxiliary winding voltage becomes higher. Are there any solution for this problem?

Best Regards,
tateo