Other Parts Discussed in Thread: TUSB1002A
Hi team,
My customer reported an issue that the system wake-up on itself after entering S3 from S0 with large fail rate when: connecting an USB disk to 2547 charging port and mouse to another USB-A port but both do nothing ==> manually turn PC into S3 and see the system wake-up to S0 again. Connecting the USB disk to other USB3.0 non-charging port will not see the issue.
Schematic as below: ILIM_SEL, CTL2, CTL3 are all pulled high to 5V, only CTL1 is controlled via Embeded Controller.
It should be in CDP/DCP_Auto with load detection.
In normal case, S3 signal is triggered and kept low:
In fail case, seems there is an USB3 signal transmission then the S3 pin is pulled-high again.
Scale-up on the changing part:
And I checked the D+/D- signal (yellow as U2P and green as U2N) to check the mode change:
Seems to me 2547 is in 2V/2.7V divider mode but not DCP_Auto after entering S3, is this behavior correct?
Scale-up on the Vbus drop part, seems D+/D- changed after S3 signal.
Attach the un-scaled version if you'd like to check the whole process:
I also confirmed CTL1 waveform as below and seems it is working as expected after entering S3:
Scale-up and seems that S3 is leading the process.
So in short, USB3 signal appears ==> S3 signal changed ==>2547 mode changed. But seems that in the OK case, there is also USB3.0 signal after entering S3.
Due to the limitation on the board I'm not able to captured the Ibus current. Could you kindly help to analysis and suggest what is the possible cause of the issue? Is our charger part of the issue? And if any test we could do to clarify if it is USB communication related or others?
It will be helpful if you could also help to explain the conditions that could trigger the wake-up process by 2547. I saw a power-detection and a HID but actually don't know which one should I focus regarding this case.
Thanks very much for your help.
Max