TPS65987D: TPS65987D + TPS55288 Schematic review

Hi Cho,

What is the use case for this design?

• What kind of product is being made
  • Is this port supplying power, charging, providing/taking data?
• Are you looking to source power/sink power, both?
• Any data requirements
• How much power is desired for source/sink?

Please go through the attached spreadsheet. Red items need to be fixed, Yellow are recommended, and Green are good.

Comments:

It seems like the flow of power in this design is off. When designing the power path for a Source device, power should come from the output of a power supply, go into the PPHV(1 or 2 depending on design) pass through the internal power path, exit the TPS65987 from the VBUS pin(1 or 2 depending on design), and exit through the VBUS pin of the Type-C connector. In the shared design, the output of the power supply is connected directly to the Type-C connector.

The image below is from the 987EVM user manual, and is not an exact representation of your system. I added it to highlight the power path connections.

Additional Comments/questions

• If this is a source application, you may need to change the capacitors on PP_HV(see lines 8-11 of spreadsheet)
• Did you choose the FTDI MCU from the 987EVM?
  • We do no support the design around that part. We recommend either following the EVM schematic exactly or reaching out to FTDI.
• There are many GPIOs that have unattached nets.
  • Is this intentional (i.e. separate sheet?)
• If you are a source, you will need a separate 5V source for the PP1_cable pin. Please refer to 8.3.1 in the datasheet for why it is required.

Thanks and Regards,

Chris