TUSB8042A: VDD33 has a leakage from VDD

William Hu

Part Number: TUSB8042A

When P3V3_AUX is not ready,there is a leakage from VDD3. P3V3_AUX looks good when NOPOP L13USB3.Do you have any comments and suggestions?

0 William Hu 3 months ago

After L13USB3 removed, P3V3_AUX looks goood.

0 Brian Zhou 2 months ago in reply to William Hu

Can you take waveform with GRST, 3.3v and 1.1v together?

Best

Brian

0 William Hu 2 months ago in reply to Brian Zhou

Hi Brian,

0 Brian Zhou 2 months ago in reply to William Hu

Can customer move Vdd to after VDD3p3?

Regards

Brian

0 William Hu 2 months ago in reply to Brian Zhou

What’s the root cause? From the spec perspective, VDD should be powered up before VDD3P3.

0 William Hu 2 months ago in reply to William Hu

Here is "Vdd to after VDD3p3". Please review,thanks.

0 William Hu 2 months ago in reply to William Hu

Power off also looks good.

0 Brian Zhou 2 months ago in reply to William Hu

new power on and off sequence looks good.

Best

Brian

0 William Hu 2 months ago in reply to Brian Zhou

what's root cause and solution?Thanks.

0 Brian Zhou 2 months ago in reply to William Hu

There is Diode between VDD and VDD33, if VDD is up earlier than VDD33, there is current path from VDD to VDD33.

So it's prefer to power on VDD33 earlier than VDD and keep GRST low at least 3ms after both VDD33 and VDD stable .

Best

Brian

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