USB PD How to use Augmented PDO (APDO)

[AOhir.1603]

Hi there,

I am using the x-cube-usb-pd in TCPM/TCPC configuration (USBPD_TCPM_LIB_PD3_CONFIG_1).

My questions are:

• Is Augmented PDO (APDO) and variable PDO supported in this config? Or do we need to use USBPD_TCPM_LIB_PD3_FULL?
• If we define an APDO and we are a source, does a connected device also need to request for an APDO? Or could a device request for a fixed PDO and our device will use the APDO to provide the matching power to the connected device?

For example, our device has fixed PDO 3A@5V and APDO 3A@6V-12V. If a connected device requests for a Fixed PDO 3A@9V, would it negotiate to provide 3A@9V? Or does a connected device need to have requested for APDO 3A@9V?

• Similarly for variable PDO, if we define a fixed PDO and a variable PDO, and a connected device only has a fixed PDO, would it utilise the variable PDO or fall back to the fixed PDO?

For example, our device has Fixed PDO 3A@5V and Variable PDO 3A@6V-12V. A connected device has a Fixed PDO 3A@9V. What happens then?

Thanks,

AOF

[Yohann M.]

Hi AOF,

1) Difference between USBPD_TCPM_LIB_PD3_CONFIG_1 and USBPD_TCPM_LIB_PD3_FULL is only the support of VDM. 'CONFIG_1' supports PPS (APDO).

2) Both port partner should have in their capabilities the support of APDO. Sink device can request a APDO if a source devices APDO matches with its capabilities.

In your example, if sink device requests fixed PDO 3A@9V, Source device will reject this request and will stay to default 5V@3A. Sink connected device should request APDO 3A@9V to switch in PPS mode.

3) We did not use variable PDO in our different applications we delivered but I assume that this is the same constraint.

Regards,

Yohann