SI Analysis of USB2.0 interface of AM335X

ARM arm

Hi,

I am doing a hardware design where I am taking BBB as my reference design.

I am not finding SI Analysis model for USB Interface in AM335X IBIS Model. In no way I am doubting the routing on BBB. But on My board the distance between the USB connector and processor has become 3.8". I do not know how will the whole thing will behave so wanted a comparative study between BBB and my board for which required

Can some1 help in some way in this.

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Hi,

This length will not be an issue if you route the USB data lines as a differential pair with 90Ohm differential impedance. Also you should keep them away from traces which can induct noise on these lines, and route them over a solid non-interrupted GND plane.

0 ARM arm over 9 years ago in reply to Biser Gatchev-XID

Expert 2630 points

Hi Biser,

Th track runs all throughout GND Plane except at the end where it takes reference from the power supply plane just as in BBB.

Regards

0 Biser Gatchev-XID over 9 years ago in reply to ARM arm

TI__Guru**** 393215 points

If it's 90Ohm differential you should have no issues. After all the USB cable can be several meters long.

0 ARM arm over 9 years ago in reply to Biser Gatchev-XID

Expert 2630 points

Hi Biser,

Just to ask since it is related, can we say the same for SATA2.0 lines also. If we maintain the line tolerance within 2 mil with solid ground planes 100 ohm differential. Will that be ok too, if you could answer from your practical experience.

Regards

0 Biser Gatchev-XID over 9 years ago in reply to ARM arm

TI__Guru**** 393215 points

Perhaps this document will help: www.ti.com/.../spraar7e.pdf

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SI Analysis of USB2.0 interface of AM335X