TUSB422: Charging Dock Design

Yongki Jeong1

Part Number: TUSB422

Hi Ti team

I am trying to design as below to make a accessory that can communicate data while charging.
If there is no device on the #B side, simply proceed with charging, and when a host or device is connected to #B, USB communication is required.

Will there be any problems with this design?

Thanks!

over 1 year ago

0 Brian Zhou over 1 year ago

TI__Guru** 113810 points

do you need to charge B side?

Regards

brain

0 Yongki Jeong1 over 1 year ago in reply to Brian Zhou

Intellectual 505 points

Hi Brian

Only USB basic power (5V/500mA) is supplied to the B side.
-> For device operation and USB communication rather than charging

charging is for A side and A and B should be able to communicate.
In addition, A is always charged, and USB communication of A must start when B is connected

sincerely

0 Brian Zhou over 1 year ago in reply to Yongki Jeong1

TI__Guru** 113810 points

so USB communication is between A and B, not go though MCU.

B is device only or OTG as well?

Regadrs

Brian

0 Yongki Jeong1 over 1 year ago in reply to Brian Zhou

Intellectual 505 points

Hi Brian

On the B side, both OTG (UFP) and PC (DFP) are connected.
So A (DRP) needs to be able to recognize which device is connected to B.

In addition, regardless of the existence of device B, the power role with device A must be maintained until device A is disconnected.
- A : Sink
-Customize Device : Source

Sincerely

0 Brian Zhou over 1 year ago in reply to Yongki Jeong1

TI__Guru** 113810 points

so USB communication is only between A and B, right?

Regards

Brian

0 Yongki Jeong1 over 1 year ago in reply to Brian Zhou

Intellectual 505 points

Hi Brian

Yes, that's right

Sincerely

0 Brian Zhou over 1 year ago in reply to Yongki Jeong1

TI__Guru** 113810 points

ok, It seems pretty complicated, can we have a call?

Regards

Brian

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TUSB422: Charging Dock Design