BQ25792: Charger status ok but doesn't charge the battery.

Thomas Lochmatter1

Part Number: BQ25792
Other Parts Discussed in Thread: TPS25751, TPS25750

Tool/software:

Dear TI

We made a design with the TPS25750D PD controller and the BQ25792RQM Charger. Please see the schematic below. The PD controller works and deliver the adjusted 9V. Unfortunately, the Charger doesn't charge the battery. The STAT signal signalise, that it should charger -> the LED is constantly on.

Do you have any idea, where the problem could be.

BR Thomas

over 1 year ago

0 Christian Moyer over 1 year ago

TI__Mastermind 31816 points

Hello Thomas,

Can you provide your register values?

Best Regards,

Christian.

0 Thomas Lochmatter1 over 1 year ago

Prodigy 80 points

Hello Christian

Meanwhile, the charger seems to work. We adjust with the tool 9V / 3A.

Charge termination voltage: 8.39V

Charge current: 3 A

End of charge current: 120 mA

Pre-charge current: 120mA

The charger work with 5 V but not with 9V.

BR Thomas

0 Thomas Lochmatter1 over 1 year ago in reply to Christian Moyer

Prodigy 80 points

Hello Christian

It looks that we found the mistake... The CC lines must be not connected to the protection diode D301.

What do you suggest to connect to the pin PP5V of TPS25750D if we not use the source mode? Can we let this pin open?

BR Thomas

0 Thomas Lochmatter1 over 1 year ago in reply to Christian Moyer

Prodigy 80 points

Further, according to the forums, more or less everybody suggest to replace the TPS25750D by the TPS25751D. What is you estimation. Shall we do that or is the TPS25750D available in the next years?

0 Christian Moyer over 1 year ago in reply to Thomas Lochmatter1

TI__Mastermind 31816 points

Hello Thomas,

I'm going to assign this question to the USB-C PD team to answer your questions related to the TPS25750D.

Best Regards,

Christian.

0 Christopher Lim1 over 1 year ago in reply to Christian Moyer

TI__Mastermind 37855 points

Hi Thomas,

Thomas Lochmatter1 said:
What do you suggest to connect to the pin PP5V of TPS25750D if we not use the source mode? Can we let this pin open?

This thread has a similar application (sink only). In this case, PP5V can be grounded.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/988215/faq-tps25750-how-do-i-create-a-sink-only-usb-c-pd-port-to-replace-a-legacy-barrel-jack-connector?tisearch=e2e-sitesearch&keymatch=tps25750#

If you are far into a design and can't switch, the part should be available. But, if possible, we highly recommend switching to the TPS25751 for any current or new designs. It will have the latest support and bugfixes. See the following thread for more info.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1346998/faq-tps25751-migrating-from-the-tps25750-to-the-tps25751?tisearch=e2e-sitesearch&keymatch=tps25750#

Thanks and Regards,

Chris

0 Thomas Lochmatter1 over 1 year ago in reply to Christopher Lim1

Prodigy 80 points

Hi Chris

We will change to the new TPS2751D part. Can the design be adopted one-to-one?

0 Christopher Lim1 over 1 year ago in reply to Thomas Lochmatter1

TI__Mastermind 37855 points

Hi Thomas,

The schematic and hardware can remain the same. The TPS25751 does use a newer GUI, so the firmware image will change, but it is similar to the one for the TPS25750.

Thanks and Regards,

Chris

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BQ25792: Charger status ok but doesn't charge the battery.