TUSB8020B: Power Up timing

user6390769

Part Number: TUSB8020B

Hi E2E

In VDD33 and VDD power-up timing, the ramp of VDD33 at our system is slow, the rising of VDD is about 8ms faster than VDD33.

In datasheet, "VDD33 stable before VDD stable", if VDD33 stable after VDD stable, what kind of impact can you expect?

The GRSTz is rising after about 50ms VDD33 stable.

Regards.

0 JMMN over 3 years ago

As long as GRSTz is held low after both power rails have ramped, there should be no issue.

Regards,

JMMN

0 user6390769 over 3 years ago in reply to JMMN

Hi JMMN

Thank you for your comment. But Td1 shown in "Figure 1. Power-Up Timing Requirements" needs more than 0ms.

If the GRSTz is held low, is Td1 no-issue?

Regards,

+1 JMMN over 3 years ago in reply to user6390769

Yes, there is the note: No timing relationship between VDD33 and VDD

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