USB-PD Sink support

[riteshpatel]

Hi,

I am looking for the USB-PD sink support in my custom board.

The power delivery requirement at a glance:

• USB-PD support on Type C connector
• Default Sink/Consumer power role, No power role swap required
• No USB data communication over this port.
• The system requires ~33W power after power negotiation

Based on the above requirements, PTN5110 looks a good option to me, refer section  8.1.7 USB PD Sink.

Few questions on the application diagram shown in section 8.1.7:

1. Does USB-PD provide 5V by default before required power negotiation to power the TCPM MCU and MCU then negotiate high power, ~33W in our case for the system?  I mean 5V at output of NX20P5090 by using pre-configured PTN5110DHQ as a Sink role at POR.
2. Is the MCU (TCPM PD POLICY CONTROLLER) is a specific USB-PD controller or an ordinary MCU with I2C interface can work?
3. How the PTN5110 negotiates with the USB-PD source for the required power? What are the components/interfaces being involved during the negotiation?
4. Vbus to short protection, USB-PD PHY and the external power switch are considered as USB-PD sink components. Already have one Cortex-M MCU in the system for TCPM. Is anything else required for USB-PD sink support to my design?

Thank you.

[TomasVaverka]

Hi Ritesh,

Thanks for your interest in the PTN5110(N)DHQ! 

Here are the answers to your questions:

1. Yes, by default safe 5V is provided for backward compatibility.

2. NXP recommends using either Kinetis, LPC or i.MX RT MCUs to execute PD firmware which is part of the MCUXpresso SDK.

3. The PTN5110 PD PHY drives the communication across the CC lines. On the MCU runs the PD firmware that supports the PD negotiation and communicates with the PTN5110 over I2C lines to perform functions such as requesting power level. So NXP's solution separates PD manager and PD PHY.

4. No, it is all you need for your application.

Best regards,

Tomas

[riteshpatel]

Thank you Thomas for your detailed response. 

The MCU is finalized by our customer, so we cannot change the MCU now. Its STM32L5 cortex-M33. 

Let me know how we can support PTN5110 USB-PD firmware on STM32L5.

[TomasVaverka]

Hi Ritesh,

I am afraid that for non-NXP MCU I can only refer to the PTN5110N PD PHY application programming guide.

Best regards,

Tomas