TPS25750: design with BQ25792 - is PP5V input neccessary for sink and source application?

Schroedinger Karl

Part Number: TPS25750
Other Parts Discussed in Thread: BQ25792, TPS25751, TPS54531

Tool/software:

Do I need a PP5V input to the TPS25750D (applcation with BQ25792)? In the user giude "slvubz4_TPS25750_userguide.pdf" there is a solution shown w/o such input (page 3, right side of fig. 2-1) also for sink and source application. In other documents a 5V/5A supply for PP5V is used. Why can the BQ25792 not generate this voltage for the USB output (VBUS)? Or is the 5V needed for the TSP25750 internally?

Best regards

over 1 year ago

0 Raymond Lin over 1 year ago

TI__Mastermind 34046 points

Hi Schroedinger,

PP5V input is used for the internal 5V source only power path as well as supplying power for the CC logic and Vconn when required. This PP5V is used to supply 5V for Type-C source as well as the PDO1 of 5V/3A. Figure 2-1 is from an older version of the TPS25750 GUI that is not available to select.

As a side note, for new designs we recommend using TPS25751 over TPS25750. Please refer to this FAQ page on the migration and the difference between these two parts: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1346998/faq-tps25751-migrating-from-the-tps25750-to-the-tps25751

Thanks and Regards,

Raymond Lin

0 Schroedinger Karl over 1 year ago in reply to Raymond Lin

Prodigy 160 points

Hi Raymond,

o.k., thanks. I have seen the recommendation for TPS25751, but it is not available at the moment.

The proposed TPS54531 for the PP5V as well as the PP5V input take a lot of power when not used (too much for my application). What happens if I shut down PP5V during "sleep mode", i.e. no sink or source is connected to USB. Is it possible to have a wake up when USB sink or source is connected?

Regards

Karl

+1 Raymond Lin over 1 year ago in reply to Schroedinger Karl

TI__Mastermind 34046 points

Hi Karl,

If PP5V is not present then the internal CC logic for TPS25750/1 will not be powered until VBUS comes up high. During this time when PP5V is not present TPS25751 can only act as a sink. For PP5V you only need a 3A capable 5V DCDC (or 3.6A if Vconn is required).

You could use certain GPIO event (i.e. plug event) to know when a cable is connected and then power back on the DCDC, however if the timing is not align it could cause connection issue unless an EC is present to handle the transition.

Thanks and Regards,

Raymond Lin

0 Schroedinger Karl over 1 year ago in reply to Raymond Lin

Prodigy 160 points

Thanks a lot.

Karl

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TPS25750: design with BQ25792 - is PP5V input neccessary for sink and source application?