TPS25750: SWAP Sink to Source

Hi Thierry,

Is this a new design? If you are in development or starting a new design, we strongly recommend using the TPS25751, which is the successor to the TPS25750.

Is this a custom board or are you using the TP25750EVM?

Can you share the .json file you are using?

Do you have a PD analyzer and can you provide a PD log of the issue seen?

Thierry Quetineau said:

I reach to set the TPS25750 for work as SINK mode because I set this mode as prefered with the Application tool.

When you set Sink as the preferred power role, it will attempt to swap to sink whenever in a Source mode. If the phone is capable of sourcing, it may end up as the source if it does not reject the power role swap request. In this case, you would 

Thierry Quetineau said:

I send the command "SWSr" for change role to source but it seems stay in sink mode.

Does the command execute correctly? A PD log would help to see if the role swap request is going through. It might request and complete the swap, then immediately try to swap back due to the preferred power role.

Thierry Quetineau said:

The most incredible is that VBUS is arround 13V like the mobile is as a charger because the TPS is in sink mode (but the switch is not close due to only 5V or 20V PDO).

The phone is generating 13-V? That seems abnormally high. That would likely be an issue with the source, so if the TPS is sink and only requesting a 5-V contract, it might be a mobile issue.

Thierry Quetineau said:

Is "RX_SOURCE_CAPS" is the source capacities of the device connected?

Yes

Thanks and Regards,

Chris

Hi Christopher,

Yes it's a new design. The problem is the TPS25751S availability. Can't find it in Mouser or other. Can I order samples?

I don't have PD analyser yet but I will have a look to buy one. Any recomendation?

I am using the MikroE board for evaluation.

- Prefered Power Role: you suggest so to set "source" as preferred power role? I can try and test again.

- "SWSr" : The command should be correctly executed because it return "0". I also saw some consumtion during few instant on my power supply. This confirm that the controller have probably switch to source and then back to sink (preferred) for any reason. 

- 13V : I saw 13V but after a power cycle I don't reproduce it. VBUS was staying at 5V. 

- "RX_SOURCE_CAPS": So, the mobil capacity is 5V 1,5A source cap. But why the RX_sink is 0? Is it because the mobil is in source mode?

This is the json file

{"questionnaire":{"version":"7.0.4.7","answers":[3,0,4,1,3,3,1,null,1,null,null,null,null,null,null],"options":{},"configID":"0000","vendorID":"0000"},"configuration":{"data":{"selected_ace":[{"register":6,"data":[0,0,0,0,0,0,0,0]},{"register":22,"data":[10,48,48,77,0,0,0,0,0,0,3]},{"register":50,"data":[1,168,42,100,144,1,38,44,209,2,0,44,177,4,0,244,65,6,0,0,0,0,0,0,0,0,0,0,0,0,0]},{"register":51,"data":[2,44,145,1,0,244,65,6,0,44,177,4,0,244,65,6,0,69,65,6,0,0,0,0,0,0,0,0,0]},{"register":92,"data":[50,0,0,0,1,0,0,0,0,16,0,0,0,0,0,0,48,0,0,0,0,0,0,0,0,12,0,0,0,0,0,0,0,0,0,0,100,75,0,0,0,0,0,0,0,0,0,0,0]},{"register":117,"data":[0,0,0,0]}]}}}

But the low region file save was before save the application tool file. So I maybe have to make again the LR file.

Anyway, sending the "SWSr" commande, it should swap to Source mode?

BR

Thierry

Hi Thierry,

Thierry Quetineau said:

Yes it's a new design. The problem is the TPS25751S availability. Can't find it in Mouser or other. Can I order samples?

The part just released so it should be available, or be available soon. You would need to contact your regional TI sales office and they should be able to assist you in ordering samples.

Thierry Quetineau said:

I don't have PD analyser yet but I will have a look to buy one. Any recomendation?

Unfortunately, we do not have a good recommendation at this time. We originally recommended the TotalPhase Power Delivery Analyzer, but they have recently discontinued it. We are still looking for a good alternative. This is not an official recommendation, but I have found the PowerZ to be a cheap useful tool that can do basic PD. I have not used it too much for the PD analyzer function, but have found the power sink capabilities useful.

Thierry Quetineau said:

I am using the MikroE board for evaluation.

I'm not familiar with this, could you send a link?

Thierry Quetineau said:

- Prefered Power Role: you suggest so to set "source" as preferred power role? I can try and test again.

This is worth a try, but you do risk seeing the opposite behavior when wanting to sink power.

Thierry Quetineau said:

- "SWSr" : The command should be correctly executed because it return "0". I also saw some consumtion during few instant on my power supply. This confirm that the controller have probably switch to source and then back to sink (preferred) for any reason. 

Yeah, the PD log would better indicate this behavior, but this does somewhat confirm my suspicions. If you look at the TPS25751 TRM, there is a "Initate Swap to Sink" field in the Port Control register. This is what is likely initiating the swap back. You may be able to clear the bit, but it is only possible over I2C as the GUI always enables one of the "initiate swap to xxx" bits. You would need to manually configure this bit on and off if you do want to primarily be a sink device.

What GUI version are you using? Could you share the json in the file format? I'm having issues loading it into the 7.0.4 GUI version.

Thierry Quetineau said:

Anyway, sending the "SWSr" commande, it should swap to Source mode?

Yes, but as mentioned above, it does not prevent the port from swapping back to Sink mode.

Thanks and Regards,

Chris

Hi Chris,

MikroE board: https://www.mouser.es/ProductDetail/Mikroe/MIKROE-5682?qs=17ckDYBRdenIBQxkWz4Svw%3D%3D

I found the KM003C and already order it for try (not in Amazon Europe because too expensive). But I should received it on April 19.

GUI version: as the copy/paste config wrote: "version":"7.0.4.7"

How I can share the json file? "Insert" menu don't give me any browser option for select a file.

I will try clearing "initiate swap to sink" bit over I2C.

BR

Thierry

Hi Chris,

I just read the Port_Ctrl bytes and both "initiate swap" bit are =0.

Both "Process swap" are =1

Connecting the mobil phone, VBUS is 5V and the external switch is "On". So, mobil is in source mode and device in sink mode. 

I must try forcing device in Source mode from default setup (GUI).

Thierry

Hi Gary,

Thierry Quetineau said:

How I can share the json file? "Insert" menu don't give me any browser option for select a file.

I usually just drag it directly into the thread from file explorer. (ie. download the .json to my downloads folder, drag the .json from downloads directly into the E2E thread)

Thierry Quetineau said:

I just read the Port_Ctrl bytes and both "initiate swap" bit are =0.

Both "Process swap" are =1

Connecting the mobil phone, VBUS is 5V and the external switch is "On". So, mobil is in source mode and device in sink mode. 

I must try forcing device in Source mode from default setup (GUI).

Can you share the register read information so I can confirm? Did you clear the "initiate swap" bits or were they already cleared?

If you cleared the bits, try the 'SWSr' command after knowing the bits are cleared. If they system still ends up with the device as a sink, and the mobile as the source, it may be the mobile that is requesting the power role swap (after you try to swap it with the SWSr command)

Unfortunately, without the PD log it is a little difficult to determine who is causing what.

Another thing you may want to try for testing is to:

1. connect the devices
   1. devices default to TPS25750 Sink, mobile Source
2. clear both "initiate swap..." bits
   1. Try SWSr now and report if the role swap is successful
3. If 2 fails, and the TPS25750 is still sink, clear the "process swap to sink bit"
   1. Try SWSr now and report if the role swap is successful
   2. If this works, it is likely the phone that is swapping back.

Thanks and Regards,

Chris

Hi Chris,

First I found why I measure 13V as I say on previous message. I was on wrong mosfet pin. 13V is the gate voltage. Make sens.

I try the following this morning.

- Read the Port Ctrl

- Force both bit for sink at 0 (initiate and process swap)

- Force both bit for source at 1

- send SWSr command

The mobile is charging now!!

So, I will change the patch bundle setting to source mode preferred and try it with both type of external device: mobile and power supply.

I imagine that if the power supply is logicaly not able to sink (with TPS set as source), the TPS will swap to sink.

I will tell you result asap.

I have drag and drop the .json file but I can't see it on my message. Tell me if you have it.

BR

Thierry