TPS65987D: USB-C-PD-DUO-EVM

Hi Rex,

I believe you can do this but you will have to negotiate a 20V contract from the Source Duo board first before the TPS65988 EVM can source power to the Sink Duo board. How did you program the power duo boards? Could you please reprogram them and try again making sure you follow the Power Duo EVM User's Guide that describes the programming portion as you have to select the Source/Sink project configurations in the GUI? I believe there is also a jumper that you will have to move when you program the boards.

Thank you,

Hari

Hi Hari,

I did is flow the Power Duo EVM User's Guide that describes the programming portion to program the source and Sink board. However, it is not working. Only the up stream  work, but the down stream  TPS65988 EVM to sink is not working. Do I need to rearrange the  TPS65988 EVM jumper or select specify program for it? Thanks .

Best,

Rex

Hi Rex,

Yes if your source and sink boards are configured correctly, you will then need to make sure the TPS65988 EVM is programmed correctly. As a quick check for the Power Duo boards, you can test them by connecting the source board to the sink board via type-c cable to see if you can negotiate all of the voltages. 

For the TPS65988 EVM, you will have to program it via the GUI with the correct configurations and then power cycle the board. What settings are you using for the TPS65988 EVM?

Thank you,

Hari

Hi Hari,

I already test the Power Duo boards, and it works well. For the TPS65988 EVM, I program it via the GUI as the TPS65987D and flow the user guide to set up the jumper. The Power Duo board's source connect to port A, and the TPS65988 EVM's port B connect to the sink board. Is it a wrong configurations for the TPS65988 EVM? 

Thank you,

Rex

Hi Rex,

Yes I suspect there may be some incorrect configurations in the register settings. Could you please attach your GUI project file here and I will take a look at it?

Thank you,

Hari

Hi Hari,

The attachment is the TPS 65988 EVM board project file I used. For the Power duo board, I just use the example project source and sink. Thank you!

Best,

RexTPS65988.pjt 

Hi Rex,

I think the issue was that the TPS65988 config was set to be in 87 Emulation Mode, please uncheck this bit and reflash the board. You will also have to power cycle it and it should work.

Thank you,

Hari

Hi Hari,

I try it. It is still not works. For the USB-C-PD-DUO-EVM, do I need to do the special programming? Right now, I use the example project source and sink  to program it. Thank you!

Best,

Rex

Hi Hari,

I try it. It is still not works. For the USB-C-PD-DUO-EVM, do I need to do the special programming? Right now, I use the example project source and sink  to program it. Thank you!

Best,

Rex

Hi Hari,

One more thing, the TPS65988 EVM board's jumper configuration is it correct? 

Hi Rex,

Yes it seems like you may have to change your power path configurations. Although you have selected source or sink for all of them, could you please change them to match the image I attached earlier for PP1-PP4 Switch Configs and retest?

Also, did you power cycle the board after you reconfigured and flashed it?

Thank you,

Hari

Hi Hari,

I flow your instruction to change the power path configuration and retest it. It is still not works. I did power cycle the board every time after reprogramed.

Thank you,

Rex

Hi Rex,

To confirm, you are first powering on the Power Duo Source board and then connecting it to the TPS65988 EVM and sourcing a 20V contract to it. From there, you connect the Duo Sink board to the other port of the TPS65988 EVM which is where the issue occurs as you are unable to sink power to the Sink Duo board. Is this correct? Are you able to check LDO_3V3 on the tPS65988 EVM board to see if it's powered?

I think I will need some PD logs of both ports from a Total Phase Analyzer or similar to debug more to see what the issue could be. Could you please provide this and also scope captures of VBUS1, VBUS2 and CC lines?

Thank you,

Hari

Hi Hari,

Yes, it is correct. And the LDO3V3, 1V2,5V are works well. I can check the power of that. And I attached the CC lines picture, but I can not get the correct respond of it. And I also attached the project file of the TPS65988 EVM board and the Power duo Board Source and sink file. I hope it help. Thanks

Best,

Rex

1070.TPS65988.pjtSource.pjtSink.pjt

Hi Rex,

I have some recommendations on your project file, I'm not sure which port you are using for sourcing/sinking and I think to make it simpler, could you please change the Power Swap Strategy field for both ports to "No Preference, Supports all swaps"? This way no matter which board you are connecting to it, it will accept the role if the duo board requests a power role swap. Also, for the port you will be sinking power into, you may also deselect the Externally Powered bit. If those two options don't seem to help then I will need the PD logs to evaluate further to see the communication between the two devices.

Thank you,

Hari

Hi Hari,

Thank you for your quick respond. I try those two method. It still not work. And I found out the TPS65988 EVM board Q16 (SSM6J507NU) is short out. Is it will affect the function which I want to test? 

And I use the power duo board source side connect to TPS65988 EVM  port B. The TPS65988 EVM  port A connected sink side of the Power duo board. For the CC2 of port B look like nothing send over, CC1 and VBUS looks good. Then for the port A CC1 and CC2 looks not work at all. Thanks

Best,

Rex

Hi Rex,

Yes unfortunately, this component is part of the overall power system on the EVM and therefore, I think it may be the cause of your issues. If you are able to collect PD logs of the behavior it may confirm but I would recommend to isolate this issue altogether, it may be better to use another TPS65988 EVM.

If your design will be for PD only and no alternate modes, I would also recommend looking into the TPS25750. However, this device will only have 1 port so if you need another port, you will have to get 2 of them.

Thank you,

Hari

Hi Hari,

Thank you for your advise. The design will be used Thunderbolt controller, so I think the TPS65988 is best option for me to due with. I will get another try when I get a new board. Thanks.

Best,

Rex