HD3SS3220: How to use USB_ID pin in DRP implementation

chethan md

Part Number: HD3SS3220

Tool/software:

Hi,

I am using HD3SS3220IRNHT part in my design along with i.MX8 SOM for the USB Type-C DRP application with USB3.1 Gen1 (5Gbps).

I would like to know how can I make use of the USB_ID pin from the i.MX8 SOM along with HD3SS3220IRNHT for the DRP application.

Also, Attached my schematics for the review.

Thanks,

Chethan.

2 months ago

0 chethan md 2 months ago

Intellectual 840 points

T177.pdf

0 chethan md 2 months ago in reply to chethan md

Intellectual 840 points

refer to pages 7 and 14.

0 Brian Zhou 2 months ago in reply to chethan md

TI__Guru** 116870 points

Hi Chethan:

For DRP, please look at Figure8-1 in datasheet.

First , a vbus switch is needed to supply Vbus for USBC port.

2nd: ID pin is used to control Vbus switch.

Regards

brian

0 chethan md 2 months ago in reply to Brian Zhou

Intellectual 840 points

Hi Brian,

Do you suggest to control the VBUS switch directly from the ID pin of hd3ss3220irnht(of course the ID pin is still routed to Host for Host/Device functionality decision making but the host does not control the VBUS switch in this case) or do you suggest to route the ID pin to the Host and then using GPIO Host controlling the VBUS switch? which is the preferred option?

Thanks,

Chethan.

0 Brian Zhou 2 months ago in reply to chethan md

TI__Guru** 116870 points

Hi Chethan:

I suggest to control the VBUS switch directly from the ID pin of hd3ss3220irnht. ID pin is not necessary routed to Host.

But you need to pick a vbus switch with low enable.

Regards

Brian

0 chethan md 2 months ago in reply to Brian Zhou

Intellectual 840 points

Hi Brian,

Thanks for your response, I understand your suggestion to use the ID pin to directly drive the VBUS switch (in my case I am using TPS2541ARTET which has an active HIGH enable pin but I am using a MOSFET to invert the logic--I believe it is okay).

I have a couple of doubts/Concerns with this implementation.

1. How does my Host know (in my case iMX8 SOM) that it needs to be Host or Device until the ID pin information is provided to the Host?

2. If the HD3SS3220IRNHT directly controls the TPS2541ARTET switch, how can the switch be turned OFF if there is an over-current scenario?

Thanks,

Chethan.

0 Brian Zhou 2 months ago in reply to chethan md

TI__Guru** 116870 points

Hi Chethan:

chethan md said:
How does my Host know (in my case iMX8 SOM) that it needs to be Host or Device until the ID pin information is provided to the Host?

For DRP, you do need connect ID to host or SOC , when ID is high, it configured as device. When ID is low, it should be host or DFP.

chethan md said:
If the HD3SS3220IRNHT directly controls the TPS2541ARTET switch, how can the switch be turned OFF if there is an over-current scenario?

for overcurrent, you do need to use SOC to control Vbus switch.

Regards

Brian

0 chethan md 2 months ago in reply to Brian Zhou

Intellectual 840 points

Hi Brain,

Understood your suggestions, I have implemented the design now, can you take a look a look. I have provisioned to control the VBUS switch from Host as well as directly from Host. Also the ID pin is connected to the Host.

Can you take a look at my Schematic and comment if it would work.

Thanks,

Chethan.