TPS65987D: Voltage negotiation switching

Ambroise Suter

Part Number: TPS65987D

Hello,

We have an issue with using the TPS65987D as the source to power a device with a TPS65986. As you can see below, the negotiation jumps back to 5V from 12V and it's unclear why:

Here how it should look (see line 41)

How it looks once running:

As you can see at line 42 it jumps back to 5V.

In addition find a scope shot of CC1 at that moment:

These test are being done with a TPS65987EVM.

Do you know hat could be an issue?

Thank you and best regards,

Ambroise

over 3 years ago

0 Prajith Cheerakkoda over 3 years ago

TI__Expert 7700 points

Hi Ambroise,

Looks like the PD controller is entering error recovery. Could you check FW log?

what is connected on the far-end? TPS65986 EVM or customer board?

Thanks
Prajith

0 Ambroise Suter over 3 years ago in reply to Prajith Cheerakkoda

TI__Expert 3820 points

Hi Prajith,

Attached is a customer board with TPS65986.

Find attached the logs and FW. Let me know if you need something else.

Thank you for your support,

Ambroise

log1_pd.ccgx log2_pd.ccgx DFP_Source_Only.pjt

0 Prajith Cheerakkoda over 3 years ago in reply to Ambroise Suter

TI__Expert 7700 points

Hello Ambroise,

Does this issue occur only with TPS65986 ? Have you tried to reproduce it with any other EVMs?

I can see that the issue occurs right after Discover mode command. Did you try disabling DP capability ?

what i asked in my previous post is FW log. Please find pic below on how to capture FW log.

Interface

Interface forum

TPS65987D: Voltage negotiation switching