TPS25750: Cannot detect plug state

Michiaki Tanii

Part Number: TPS25750

Hi team,

Our customer is facing the problem that the device cannot detect plug state appropriately after the clear Dead Battery Mode.

Could you kindly advise how to do it ?

They see the issue in the below condition.

TPS25750 is connected to USB device (USB2.0) and Tablet (USB PD, USB2.0)
The tablet is sink of USB PD / DFP, EVM board is source of USB PD and USB device is UFP

Procedure

Those are connected as below in the situation that is not turned ON power supply.
USB – EVM – tablet
Turn on only USB device and tablet.
After that, turn on EVM.

At 2. Situation, USB device and tablet can communicate with USB2.0

At 3. Situation, customer expectation is that the EVM is getting as source and table is getting as sink and then the EVM charge the tablet but the EVM isn’t able to charge the table.

Customer confirm that after power supply, the EVM is getting dead battery board and then enter DBfg command to TPS25750 and Dead Battery Mode is able to be cleared.

When Dead Battery Mode is cleared, STATUS Resister bit 0 shows No plug is connected, and it isn’t able to detect connecting the tablet.

Therefore, it isn’t able to be source by Role Swap.

We would much appreciate it if you are willing to give us any advice.

Thank you and best regards,

Michiaki

over 4 years ago

0 Kedar_Sirdeshpande over 4 years ago

TI__Expert 3370 points

Hi Michiaki,

Could you please share the project (".pjt" extension) file that the customer is using for his testing?

Regards,
Kedar

0 Kedar_Sirdeshpande over 4 years ago in reply to Kedar_Sirdeshpande

TI__Expert 3370 points

Hi Michiaki,

Is the issue resolved? Could you please provide the project configuration file and also PD communication logs during this sequence ?

Regards,
Kedar

0 Michiaki Tanii over 4 years ago in reply to Kedar_Sirdeshpande

TI__Expert 4640 points

Hi Kedar,

We got some update from customer as the below and attached.

They think something other command is needed at that time when they use GAID command to remove Dead Battery Mode and they would like to know what command is needed.

Thank you and best regards,

MichiakiTPS25750_20210812.pptx.xlsx

0 Kedar_Sirdeshpande over 4 years ago in reply to Michiaki Tanii

TI__Expert 3370 points

Hi Michiaki,

The correct command to clear Dead Battery mode is the "DBfg" 4CC command. GAID will reset the PD.

Regards,
Kedar

0 Michiaki Tanii over 4 years ago in reply to Kedar_Sirdeshpande

TI__Expert 4640 points

Customer tried the test with DBfg command but Plug status wasn’t able to be detected (bit0 = 0) and confirmed status resister(0x1A) at 0x0000000020 after executed DBfg command.

They also confirmed that it can detect Plug state and charge the tablet in case of procedure that doesn’t enter into Dead Battery Mode so they believe there is no problem for the connection.

And after excecuted DBfg command, they confirmed it can charge the tablet if USB cable between tablet and EVM is disconnected and connected.

They don’t want to disconnect and connect after clear Dead Battery mode and they want to know what command will be needed.

Also they don’t use code composer studio because they use TeraTerm on PC and control the resister as you know.

Thank you and best regards,

Michiaki

0 Kedar_Sirdeshpande over 4 years ago in reply to Michiaki Tanii

TI__Expert 3370 points

Hi Michiaki,

If the PD is entering a DB mode, can you try to keep a 500ms delay after detecting APP mode and DB flag in boot status before issuing the DBfg command?

Does the configuration have "Try.Src" enabled?

Regards,
Kedar

0 Michiaki Tanii over 4 years ago in reply to Kedar_Sirdeshpande

TI__Expert 4640 points

Hi Kedar,

Let us double check for the delay but customer think there is enough delay for 500ms because DBfg command is issued with Teraterm by only executing DBfg command with manual.

Can customer think that it is needed to read resister of APP mode and boot status before issuing DBfg command. Is that correct ?

Please let us know if there are some operation before issuing DBfg command.

Thank you and best regards,

Michiaki

0 Kedar_Sirdeshpande over 4 years ago in reply to Michiaki Tanii

TI__Expert 3370 points

Hi Michiaki.

DBfg command can be issued only in APP mode in any case. Check POWER_PATH_STATUS.PowerSource == 0x01 (PD powered by VIN 3V3). If this is set, only then should DBfg command be issued.

-Kedar

0 Kazuto Tatsumi over 4 years ago in reply to Kedar_Sirdeshpande

TI__Intellectual 2820 points

Hi Kedar,

This is Kazuto, reporting to Tanii-san as AFAE. Thank you for your support.

The issue was resolved by the diode forwarded from VBUS to VSYS_PWR. When the Dead battery mode cannot be released, PD_STATUS.ErrorRecoveryDetails=0x04, therefore the diode between VBUS to VSYS_PWR was implemented to avoid over voltage on VBUS before system power-on.

Regards,
Kazuto

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TPS25750: Cannot detect plug state