TPS65986: USB C port doesn't power-up connected device (continuation)

Isaac Brondz

Part Number: TPS65986

Hi all,

This a continuation of issue opened 1/08/2019: https://e2e.ti.com/support/interface/f/138/p/761035/2824198?tisearch=e2e-sitesearch&keymatch=TPS65986#2824198

"We designed board using single TPS65986, which need to communicate with unpowered Mini PC, connected to USB C, and power it as well (20V, 3A).

Our board powered by the external Power Supply (barrel jack).

Problem is that USB-C port doesn't supply 20V to Mini PC."

A. Attached are CC2 captured logs for 3 cases:

Success Mini PC powering. Scenario: board is up but the Mini PC doesn’t get 20V. After that the USB C is re-connected and Mini PC is successfully powered (Reconnect success.sr)
Success Mini PC powering after board power-up (Powerup success.sr)
Mini PC powering fail after board power-up (Powerup fail.sr)

https://1drv.ms/f/s!AnBsc_2bz7JBg4MwUarXi-0Wvy2Jwg

It seems that there is some kind of "noise" that make the packets unreadable (it exist also in power-up fail case - Powerup fail.sr)

B. We try to remove 3.3V and re-apply it using the PS Enable pin for case when card is powered but doesn't supply 20V to Mini PC. It doesn't help. 20V doesn't rise.

over 5 years ago

0 Eric Beljaars over 5 years ago

TI__Mastermind 36751 points

Hi Isaac,

I am unable to download the files from the link you shared. Can you please share the PD logs with me?
Is the TPS65986 advertising a 20V source PDO?

Thanks,
Eric

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

Hi Eric

I attached the 3 files for your reference

Thanks

ArielOneDrive-2019-02-20.zip

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Hi Ariel,

What program is needed to open the .SR files? I do not have the correct software for this file type.

Thanks,
Eric

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

It is called "PulseView" application from sigrok.org/.../Downloads
(32 or 64 bit in accordance to Windows OS you use)

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Hi Ariel,

Thank you, I was able to review the logs. In the failing case, it looks like the TPS65986 is properly toggling the CC line waiting for a connection. The Mini-PC on the other end of the cable needs to present an Rp or Rd resistance on the CC line to initiate the connection. Since the TPS65986 continues to toggle, it is never detecting the connection.

Thank you,
Eric

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

Thanks Erik for the fast response.
If this is the situation, it looks like the problem is with the TPS65986, because it continue to toggle.
By the way the TPS65986 sometimes it detects and sometimes not why?

Thanks Ariel

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Hi Ariel,

The TPS65986 is behaving correctly here. It will continue to toggle until it detects a connection. The issue is that the Mini PC is not advertising the correct resistance on the CC line to indicate a connection. It seems that the behavior of the Mini-PC is changing intermittently. Since I do not know the solution inside the Mini-PC, I cannot comment on why it sometimes indicates a connection and sometimes doesnt.

Thanks,
Eric

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

Thanks Eric now I understand it better still there is one issue that I don’t understand why if we first power up our board with the TPS65986 and then we connect the mini PC it works fine but when we Power up both boards Together, mini PC connected to my board with the TPS65986 it’s failing.

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Hi Ariel,

Do you have your TPS65986 configured to support dead battery mode? What is the connection of the Rpd_G1 and Rpd_G2 pins?
It is possible that the TPS65986 is booting in dead battery mode if the Mini PC powers up first. You can check the boot flags register in the TPS65986 to see if the dead battery flag is set in that case.

Thanks,
Eric

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

Hi Eric the mini PC is being powered from my.
So there is no option that the mini PC would be powered before

The only thing I can think of is that I have boot sequence issues or as you mention configuration issue.

Can you send us example code that we can use on our board to power up the Mimi PC without the dead battery

Thanks
Ariel

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Hi Ariel,

I would suggest ordering a TPS65986EVM as a reference. The Application Customization Tool has many example templates that can be used.
As far as dead battery mode is concerned. You need to check the connection of the Rpd_G1 an Rpd_G2 pins in your schematic. They should be left floating if dead battery mode is not supported.

Thanks,
Eric

0 Isaac Brondz over 5 years ago in reply to Ariel Marcus

Prodigy 80 points

Hi Eric,
Rpd_G1 connected to C_CC1 and Rpd_G2 to CC2
1. Can I send you our schematic diagram for review to your TI mail?
2. Please send us the FW file that will eliminate the option of "dеad battery" state

0 Eric Beljaars over 5 years ago in reply to Isaac Brondz

TI__Mastermind 36751 points

Hi Isaac,

1. With Rpd_G1 and G2 connected to the CC lines, dead battery mode would always be enabled. Please remove those connections to disable dead battery mode.
2. This is a hardware change.

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

Hello Eric

It is a problem to disconnect the Rpd_G1 and G2. Since the TI original recommendation is to connect them.

Currently they are connected in the layout under the chip.

Let us know how we configure it as disconnected in the chip setup

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Ariel,

The TI EVM uses dead battery mode which is why the Rpd pins are connected to CC. It seems that you do not want to support dead battery mode. If this is the case, you need to ground the Rpd pins as desrcibed in the device datasheet.

Thanks,
Eric

0 Isaac Brondz over 5 years ago in reply to Eric Beljaars

Prodigy 80 points

Hi Eric

currently the dead battery is hard wired connected and we cannot change it on the PCBA

we see that when our board, during power-up connected to the MiniPC sometime it wake up as Sink (then the power is not delivered to the MiniPC) and sometime as source (then the power is delivered to the MiniPc)

this behave is strange !

we assume that it is somehow related to the fact that the MiniPc can act as source as well.

1. how we can make our board to act only as source and override the MiniPc configuration. force to source!

2. How we can override by sw the dead battery flag and force our system to act as source only

thanks

0 Eric Beljaars over 5 years ago in reply to Isaac Brondz

TI__Mastermind 36751 points

Hi Isaac,

If the Mini PC support PD as well, you can enable Initiate Swap to Source on the TPS65986 board. This would force the 86 to do a power role swap to become the power source. If the dead battery flag is set, you need to send the DBfg 4CC command over I2C to clear it. Then you could do a power role swap to become the source.

Thanks,
Eric

0 Isaac Brondz over 5 years ago in reply to Eric Beljaars

Prodigy 80 points

Test#7_NCR_P_Up_succ.zipHi Eric,

I have another question about alternate mode and DisplayPort.

Our MiniPC supposed to transfer DP to our board. For a reason we can't understand it doesn't happen.

I attach DP SID Status and USB-C capture (to be open with PulseView).

0 Ariel Marcus over 5 years ago in reply to Eric Beljaars

Prodigy 130 points

Thanks Eric for the answer
We will need your guidance to explain how do we send the DBfg 4CC command over I2C to clear it and how do we do a power role swap to become the source.
We are connected with the Aardvark to the 86 also what do you mean by

Thanks
Ariel

0 Eric Beljaars over 5 years ago in reply to Ariel Marcus

TI__Mastermind 36751 points

Hi Ariel,

The FW user's guide and Host Interface TRM documents can be referenced for sending I2C messages and 4CC commands to the TPS65986:
TRM: www.ti.com/.../slvuan1a.pdf
FW User's Guide: www.ti.com/.../slvuah7

Thanks,
Eric

0 Isaac Brondz over 5 years ago in reply to Eric Beljaars

Prodigy 80 points

Hi Eric,

I try to send DBfg command

In our board the Dead Battery Flag indicates false status (when the Mini PC powered or not powered):

When I try to clear this flag, command rejected

Regards

Isaac

0 Eric Beljaars over 5 years ago in reply to Isaac Brondz

TI__Mastermind 36751 points

Hi Isaac,

The DBfg command will only be accepted if the dead battery flag is set to True. Otherwise the command will be rejected. It looks like you did not power up in dead battery mode in this case.

Thanks,
Eric

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TPS65986: USB C port doesn't power-up connected device (continuation)