TUSB8044: BC1.2 failed

CK Ho

Expert 1780 points

Part Number: TUSB8044

Dear team,

Our customer is using TUSB8044, and they tested BC1.2 failed.

They referred to the EVM schematic, connect the SMBUSz (pin39) to high but without using EEPROM.

And pull the PWRCTL1234/BATEN1234 (pin32,33,35,36) to high.

Is there anything wrong??

Why TUSB8044 cannot support BC1.2??

Thanks for your comment.

over 5 years ago

0 Malik Barton57 over 5 years ago

TI__Guru 64326 points

CK,

Could you please provide more details on the failure seen for BC 1.2? What voltage are you pulling SMBUSz and PWRCTL1234/BATEN1234 to?

0 CK Ho over 5 years ago in reply to Malik Barton57

Expert 1780 points

Dear Malik,

Below is the TUSB8044 schematic.

The SMBUSz is floating (internal PU) and the PWRCTL1234/BATEN1234 are pulled up to 3.3V.

Customers feedback the BC1.2 is not enabled.

Is there any other thing we need to do for enabling BC1.2??

0 JMMN over 5 years ago in reply to CK Ho

TI__Guru 60865 points

Hi CK,

If the customer has an EEPROM installed, the battery charging setting in the EEPROM will override the pin configuration settings. Please make sure that the customer sets battery charging in Register 06h.

Regards,
JMMN

0 CK Ho over 5 years ago in reply to JMMN

Expert 1780 points

Dear JMMN,

The customer doesn't install the EEPROM, the same as the TUSB8044 EVM.

Is there any other item we need to check??

0 JMMN over 5 years ago in reply to CK Ho

TI__Guru 60865 points

HI CK,

Apologies, the schematic is very difficult to read. Do the downstream ports power on when the USB_VBUS signal is low?

Regards,
JMMN

0 CK Ho over 5 years ago in reply to JMMN

Expert 1780 points

Dear JMMN,

The USB_VBUS signal is connected a 90.9k resistor to 5V and a 10k resistor to ground.

And the GRSTz signal will assert to high when all power on ready.

0 CK Ho over 5 years ago in reply to CK Ho

Expert 1780 points

Dear sir,

May I have your feedback?

Thank you very much.

0 JMMN over 5 years ago in reply to CK Ho

TI__Guru 60865 points

Hi CK,

Please be aware that the downstream ports will only enter DCP / ACP charging modes when VBUS is low. Otherwise, only CDP charging is enabled when a USB host is connected.

Please describe how the customer is determining that BC1.2 is not enabled.

Regards,
JMMN

0 CK Ho over 5 years ago in reply to JMMN

Expert 1780 points

Dear JMMN,

Thanks for your feedback.

Yes, we just want to use CDP mode.

Would you please advise me how to simply test BC1.2 on TUSB8044??

I want to use EVM to verify.

0 JMMN over 5 years ago in reply to CK Ho

TI__Guru 60865 points

Hi CK,

There are official USB battery charging tools that are used to confirm CDP operation, or you can check the DP/DM lines for CDP handshake as described in this document: usb.org/.../battery-charging-v12-spec-and-adopters-agreement

Please be aware that many devices will not charge if the VBUS voltage level droops at all during the initial connection, make sure your system has a solid VBUS voltage of 5V to 5.25V.

Regards,
JMMN

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TUSB8044: BC1.2 failed