Hi community member,
Please let me confirm the following questions.
[Question.1]
Is there any problem that the following power domains will be powered up after inputting the USB_VBUS(5V)?
*Power domains
--> Digital Core (CVDD, CVDDRTC, USB_VDD1P3)
--> I/O (DVDDIO, DVDDRTC)
--> USB supplies USB PHY (USB_VDDOSC, USB_VDDPLL, USB_VDDA3P3)
--> LDOI
--> Analog, 1.3 V (VDDA_PLL, USB_VDDA1P3, VDDA_ANA)
*I supposed that if the device would like to fix the standard of USB2.0, the above power domains should be power-up within 100ms after the USB host detected the device has been attached.
[Question.2]
At this situation, is there risk of leaking the power to other power domains( ex. 3.3V line)?
[Background]
In case of other devices, the wiki was described this situation as below.
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When OMAPL138, as a USB device, is powered off while still connected to a powered-on host, the customer would notice leakage voltage on the 3.3V supply.
This is due to the fact there is a path between VBUS and 3.3V supply rail, that when 3.3V is not applied to the power rail, allow voltage to be leaked from powered VBUS to the 3.3V supply rail. If OMAPL138 remains to be powered off for an indefinite time, then there is a risk of long-term fatigue on OMAPL138 internal circuitry.
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From: http://processors.wiki.ti.com/index.php/OMAPL1xx,_AM1xx,_C674x,_DA8xx_USB_Hardware_Design_Guide
So, I suppose that C5535 also have the same behaviors of those processors.
If possible, please reply to me by end of today(10/25) in US time.
Best regards.