TPS65994AE: About VCONN switch control

Hi Chris-san,

Thank you for reply.

How we can read this resister explanation? I couldn't find Technical reference manual of this device on TI.com.

>But turning this off will cause a connection reset.

⇒Ths is caused by valiable of VCONN voltage over/under to any CC pin threshold. Is my understanding correct?

Best regards,

teritama

Hi Chris-san,

Sorry for asking you several times.

However, could you please give your opinion about above ?

Best regards,

teritama

Hi Chris-san,

>You can request access using this link: https://www.ti.com/secureresources/TPS65994-DESIGN
⇒Okey, I understand TRM is included in TPS65994-DESIGN file. I requested access this file, but it doesn't change the status from "pending". 
　Do we need to apply for anything else?

>You cannot make VCONN variable.
⇒I see. I understood it is difficult and not recommended to make VCONN variable.

> It is either present during the connection or not. You have to reset the connection to change this behavior.
⇒Does this means connection reset isn't caused by VCONN variable, and in the case that we controled VCONN behavior, we have to reset TPS65994AE for nomal operation?
　If we reset the connection, would manual control be required to reestablish the connection?

Best regards,

teritama

In addition, in the case of that if VCONN is set disable on resister setting and change High/Low by external circuit operation, is it required to reset connection same with case of using resister?

To which question does this answer refer?

Thanks. I understood.

What about the other two questions?

>I requested access this file, but it doesn't change the status from "pending". 
>　Do we need to apply for anything else?

>Does this means connection reset isn't caused by VCONN variable, and in the case that we controled VCONN behavior, we have to reset TPS65994AE for >nomal operation?
>　If we reset the connection, would manual control be required to reestablish the connection?

Sorry for asking you several times. Please support us to solve the customer wondering.

Best regards,

teritama

>I do not understand this question. 

⇒We want to know about when connection reset occure, VCONN supply stop until any command input to TPS65994AE from external MCU or the supply restart automaticaly.
　Which is correct?

>Connection will reset if PD changes VCONN supply OR if something outside of PD's control causes VCONN to be present. Both will cause a reset as this is not supposed to change in a typical USB-PD connection.

⇒I understand.

Best regards,

teritama

Hi Chris-san,

Thank you for cleary answer. I understand.

 In summary, is my understanding correct that the operation when VCONN is turned off from register is below?
( based on "Figure 4-15 connection state diagram : DRP" in Universal Serial Bus Type-C Cable and Connector Specification release 1.3)

1. when Type-C State is in Attached.SRC, Vconn is set to OFF by register setting.

2. Reset occurs in TPS65994AE and VBUS output stops.

3. Transition to Unattach.SNK or Unattached.SRC state, and Connection Detected is determined by the CC pin.

4. Transition to AttachWait.SRC→Attached.SRC state, and VBUS output resumes, but Vconn does not automatically resume.

In addition, when above 2. phase, reset occure on both of two USB port on TPS65994AE?

Best regards,

teritama

Hi Chris-san,

Thank you for your answer. It make sence.

Best regards,

teritama

Happy to help!