TPS65987D: overcurrent protection

K.Yaita

Part Number: TPS65987D
Other Parts Discussed in Thread: TPS55288

Hi Team,

My customer designs their USB PD DFP (Source) application with TPS65987D + TPS55288 as following SLVAEQ7.
https://www.ti.com/lit/an/slvaeq7/slvaeq7.pdf
He evaluated overcurrent protection feature of TPS65987D by connecting USB PD Sink + electric load.

If he increases electric load current, TPS65987D stops VBUS (20V) then enters an Error Recovery state.
However TPS55288 output couldn't decrease to 5V rapidly, PD negotiation doesn't occurred.

We believe the following event should be added in SLVAEQ7 for workaround for the issue.
- Detach: disable TPS55288 output & enable discharge
- Attach: enable TPS55288 output & disable discharge

Do you think it is reasonable workaround?

Best Regards,
Yaita

over 1 year ago

0 Deepak Rozario over 1 year ago

TI__Intellectual 2100 points

Hello Yaita,

Let me look into this and get back to you.

-Deepak

0 K.Yaita over 1 year ago in reply to Deepak Rozario

Guru 29690 points

Hi Deepak-san,

Thank your for your kind support.
If you need additional information or has something unclear, please let me know.

Best Regards,
Yaita

+1 Deepak Rozario over 1 year ago in reply to K.Yaita

TI__Intellectual 2100 points

Hello Yaita,

I believe the workaround you had mentioned would work.

Another method would to configure a GPIO to event 59 or 60 (HI reference Manual page 78) which would assert low when an overcurrent event occurs.
This indication can be used to enable the discharge of the DC-DC converter.

Reading the TPS55288 datasheet, in section 7.3.6 Shutdown and Load Discharge, we notice that the EN/UVLO can be pulled low to enable the discharge path. You could disabled the DC-DC using the GPIO event from the PD controller and also enable the DISCHARGE bit through the I2C command.

Regards,

Deepak

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TPS65987D: overcurrent protection