TPS65987D: TPS65987

Hi Nobert,

I'll be taking over your case, can you provide some clarification on what requirements are needed for your PJT configuration?

Thanks and Regards,

Raymond Lin

Hi Raymond,

thanks alot for your reply and your support. I have summarized the issue from the beginning. Please see the attached pdf.

I'm looking forward to your feedback.

Regards

Norbert

Summary TPS65987 Issue_221202.pdf

Hi Nobert, 

Let me test this out from my end, can you try testing out fo9rm your end if GPIO 14 and GPIO 15 respond correctly if there's only one sink PDO in your configuration. 

To clarify, test to ensure if GPIO 14 and GPIO 15 both respond when there's only a Sink PDO of 5V/1.5A and only a sink PDO of 5V/3A. 

Thanks and Regards,

Raymond Lin

Hello Raymond,

yes, both GPIOs (GPIO14 / GPIO15) work.

BTW, I'm using the Evaluation Board TPS65987EVM boards (together with your 10G-Expansion EVM boards) for evaluation in order to rule out any hardware issue in my own design.

Thank you

Regards

Norbert

Hi Nobart,

I'm working on testing your setup from my end, let me get back to you by end of the week with my results. 

Are you using the Source or Sink Evaluation boards? 

Thanks and Regards,

Raymond Lin

Hello Raymoind,

thanks a lot for your efforts. I'm using the TPS65987 EVM (SLVUB=9A)

https://www.ti.com/lit/ug/slvubo9a/slvubo9a.pdf?ts=1670478567200&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FTPS65987EVM%253FkeyMatch%253DTPS65987EVM

I tested various configurations:

a) I used a USB-C power adapter with one TPS65987EVM configured as Sink

b) I used one TPS65987EVM configured as Source and a further one configured as sink

In both set-ups the behaviour was the same.

Regards

Norbert

Hi Norbert,

It seems like we are running into similar issues on our end and will try reaching out internally to see if anyone has seen this before.

Thanks for your patience,

Chris

Hi Norbert,

Can you check what the active RDO is during these events?

Still looking into this issue internally.

Thanks,

Chris

Hello Christopher,

Sorry, but I've overlooked your last query. (I will submit the answer asap)

...as you mentioned you ran into similar issues - have you found out any reason for this behavior yet?

Thank you

Norbert

Hi Norbert,

Before we went on break, we were able to replicate your issue on our end and were working on debugging it. I'll need to verify this with a team member and re run the test, but it appeared like the gpio events were working properly and we would never enter the 2nd PDO that corresponded to GPIO 15. Let me verify the findings this week and get back to you.

I have not seen configurations with multiple PDOs at the same voltage, so there may be a chance we do not support this.

Your original question appeared to be if there was any way to differentiate between a 5V/1.5A and 5V/3A Source capability. This would require more complexity in hardware and software, but you should be able to read register 0x30(received source capabilities) over I2C from our device. We would return the raw binary values and you could decode those, similar to how we read them through the GUI.

I will continue to look at the GPIO event and try to get back to you by the end of the week.

Thanks and Regards,

Chris

Hello Chris,

please find attached a document showing the active RDO, you've asked for.

Thank you

NorbertReceived Sink-Cap_Active Contract_230120.pdf

Thanks Norbert,

I read over the initial thread again and saw that the core question was "Is there a way to differentiate between 5V/1.5A and 5V/3A source capabilities". If you are comfortable with I2C, you can read the Source capabilities and Active PDO registers from the PD over I2C, and decode the values to see what Source capabilities are being offered and the current PDO. Information on the formatting is found in the TRM, and the formatting of the PDOs can be found in section 6.4 of the USB-PD specification.

In regards to the current solution with the GPIO's:

The GPIO events appear to be working correctly. My initial thoughts are that we do not support same voltage PDOs. It seems like PDO1 is always chosen, which is why we only see the GPIO associated with it lighting up. I'll still look into contacting someone who may be able to provide more insight into this problem though.

Thanks and Regards,

Chris