TPS25750: TPS25750

For info, sending "GSrC" command seems return "0x06" code. This code is not on the datasheet list.

Thierry

Hi Thierry,

Could you send me your schematic please?

Kind regards,

Conner

USBcharger.pdf

Tell me if you can see the pdf file ( I have click and drop it).

Only is the TPS25750 part of whole design.

For debug I was connecting the USB cable and then, the 5V6 power supply.

Debug was done enough so I make the 5V6 supply automatically ON when I connect the USB cable. Like this, it work better.

during my next step of test, something  goes wrong and I burn all chips on the board. I have change them but cable detection is not working so, I need to check welds.

Anyway, can you confim that "GSrC" command should restart a negociation?

BR

Thierry

Hi Conner,

I don't know where I have the trouble now but since I change all chips affected, I never reach any negociation with my PD charger.

I2C is working and burst seems correctly loaded. I check the CC signal and I can see some communication here.

However, USB voltage still 5V instead 20V and no negociation result.

I connect the POWER-Z device for analyse the USB-C protocol. It only show "DCP 1,5A" as the burst is already set.

I am fighting with ChargerLab software tool to intend have log file but it is not working yet.

Any idea to check?

BR

Thierry

Thank you for the additional information. Yes, "GSrC" should initiate a new contract negotiation.

I will review your schematic and implementation and get back to you with a meaningful update by EOB Tuesday at the latest.

Kind regards,

Conner

Hello Conner,

I have assembled a new board because the previous one never worked again after burn chips (probably rework failure).

This new board seems working properly now.

I am testing with several external PD charger (all at least giving 20V and from 3 to 5A).

They are working despite I start the 5V (Vsys) power supply (so, processeur start after power supply is applied). The negociation seems just take quite time to be done (or with delay).

How ever, I would like to understand why the "GSrC" 4CC command return 0x06 code. This code is not on the 3.1 table in the datasheet.

I also have some I2C communication failure during the startup when I wake up all the system pluging the USB cable. I2C keep lock and no communication is possible with the TPS until power cycle. This occur after a long time switch off (some minutes).

Unpluging the cable (so, the power supply is also switeched off) and plugging it again, all work properly.

Starting with the power supply first and then plug the USB cable never give the problem.

There are some timing requirement between Vsys, 3V3, USB supply?

BR

Thierry

erraturm: "PP5V" instead "Vsys"

Hi Conner, thanks for the info.

Regard the "GSrC" error, should be not a communication error  but invalide context for this command.

I have check the power supply start and I measure 12ms between Vbus rising edge and VIN_3V3 generated by my internal power supply.

What is the maximum time for apply VIN_3V3 with no Dead battery detection? I would like to be sure that I am not border line to this situation.

However, I will manage the Dead battery flag situation.

Regard I2C bus locking, thank for advice, I will not loose more time looking for this problem on my design.

The problem is that TPS25751 is not available (dealers) for start our production. Do you have any availability date for it? 

Waiting for TPS25751, there is timing  recommandation because it seems appear only when I plug USB cable fisrt and never when I boot with my internal power supply before plug the cable.