TPS65981: USB charging issue

Stani Bell Ngoufack Tchoufack89

Intellectual 2020 points

Other Parts Discussed in Thread: TPS65981

art Number: TPS65981

Hello,

my customer did a design with the TPS65981 PD-controller in operation with a tablet and he is facing some charging issue.

The PD controller should only charge the connected tablet and act as Data UFP (i can share the application Blockdiagram offline); to enable this the configuration was made on register 0x28:

Unfortunately, we now have the problem that the tablet doesn't get charged when it is turned off.

But when I create the below configuration I have the problem that when the tablet is powered on, the Data Role is on DFP instead of UFP; but the tablet gets charged when it is switched off.

Unfortunately, there is no fixed configuration to choose from, which corresponds to Power Role = Source and Data Role = UFP.

Is there a way to enforce this somehow?

thanks for your help.

Best regards,

Stani

over 6 years ago

0 Eric Beljaars over 6 years ago

TI__Mastermind 36756 points

Hi Stani,

The tablet you are using needs to be able to support PD in order for the TPS65981 to become a Power Source and Data UFP. If the Table only supports USB Type-C and not Power Delivery, then it can only become a DFP/Source or a UFP/Sink. Power Delivery is required to complete either the Data Role Swap or Power Role Swap after the initial Type-C connection as a UFP/Sink or DFP/Source.

Thank you,
Eric

0 Stani Bell Ngoufack Tchoufack89 over 6 years ago in reply to Eric Beljaars

TI__Intellectual 2020 points

Hi Eric,

the customer is using a Samsung Tablet (SM-T510). he assume that it supports power delivery. Once the tablet is on, it works as intended with UFP / Source.

Isn't there a way to force UFP / Source? Unfortunately, register 0x28 does not provide this option.

Best regards,

Stani

0 Eric Beljaars over 6 years ago in reply to Stani Bell Ngoufack Tchoufack89

TI__Mastermind 36756 points

Hi Stani,

From the Samsung website, it does not look like that tablet supports power delivery. I would suggest using a device that supports power delivery for your testing.

If you are unsure, I would suggest getting a PD analyzer so that you can record the PD messaging between the two devices to see what is happening. This would be required for debugging a system with USB Type-C and Power Delivery.

Thank you,
Eric

0 Stani Bell Ngoufack Tchoufack89 over 6 years ago in reply to Eric Beljaars

TI__Intellectual 2020 points

Hi Eric,

thanks for your feedback regarding this. I'll discuss with the customer; however he is sure the device supports power delivery.

Is it possible or is there a way to force UFP / Source?

Regards,

Stani

0 Stani Bell Ngoufack Tchoufack89 over 6 years ago in reply to Eric Beljaars

TI__Intellectual 2020 points

Hi Eric,

could you please answer the question whether it is possible or not to force UFP / Source on the TPS65981? if yes how can the customer do this?

regards,

Stani

0 Eric Beljaars over 6 years ago in reply to Stani Bell Ngoufack Tchoufack89

TI__Mastermind 36756 points

Hi Stani,

Unfortunately, there is no way to force a UFP/Source connection as this violates the USB Type-C Specification. You would always connect as either a DFP/Source or a UFP/Sink and need to do either a power or data role swap with USB Power Delivery to become a UFP/Source.

Thank you,
Eric

0 Stani Bell Ngoufack Tchoufack89 over 6 years ago in reply to Eric Beljaars

TI__Intellectual 2020 points

Hi Eric,

thanks for your reply.

regards,

Stani

0 Stani Bell Ngoufack Tchoufack89 over 6 years ago in reply to Eric Beljaars

TI__Intellectual 2020 points

Hi Eric,

the customer just found out that if there is no connection to the tablet host, this charging issue he is facing can be remedied with a "PD Hard Reset".

Now he would like to know if it is possible to automatically generate a "PD Hard Reset" as soon as a "specific event" is present at a GPIO? there isn't any details on this in the datasheet.

thanks for your support.

Regards,

Stani

0 Eric Beljaars over 6 years ago in reply to Stani Bell Ngoufack Tchoufack89

TI__Mastermind 36756 points

Hi Stani,

You can use the "App Config" GPIO event to trigger a Hard Reset when a particular GPIO event occurs. You can read more about the App Config GPIOs in the GPIO Events App Note: http://www.ti.com/lit/an/slva838/slva838.pdf

Thank you,
Eric

0 Stani Bell Ngoufack Tchoufack89 over 6 years ago in reply to Eric Beljaars

TI__Intellectual 2020 points

Hi Eric,

the customer wasn’t able to successfully configure the function "PD Hard Reset" in case of an GPIO event. Could you please help here?

Attached is his "Application Customization Tool" project file.

The goal would be to create a “PD Hard Reset" as soon as GPIO5 goes from high to low.

Best regards,

Stani

TPS65981.pjt

0 Eric Beljaars over 6 years ago in reply to Stani Bell Ngoufack Tchoufack89

TI__Mastermind 36756 points

Hi Stani,

You would need to configure GPIO #5 as "Load App Config Set 1" in the "GPIO Event Map" register. Next, you will need to go into the "Miscellaneous Configuration Register" and under "App Config Group 1 settings". Then you can adjust the "Alt Mode Exit/ GPIO Low 4CC Command (not Task)" to "HRST"

This is all that should be required.

Thank you,
Eric

Interface

Interface forum

TPS65981: USB charging issue