3 Replies Latest reply on Aug 18, 2019 8:08 PM by ShifangZ_26

    For CCG3PA, can I have two independent sources for VDDD and VBUS_IN while having internal VBUS regulator enabled?




      Some background first:

      We have two separate power sources for VDDD (3.3V) and VBUS_IN (10-19V).  Depending on the end user, we may have both power sources enabled or just one of them (but we wouldn't know which one). The CCG3PA datasheet stated that CCG3PA can be powered by VDDD or VBUS_IN, so I don't think our multiple power options is an issue. To support all 3 possible combinations of power sources (VDDD + VBUS_IN, VDDD only, or VBUS_IN only), we have to have the internal VBUS regulator enabled.


      What I have tried:

      I made sure that I don't have pd_hal_disable_vreg(TYPEC_PORT_0_IDX) in my firmware code to ensure that the internal VBUS regulator is ON. This seems to work, as I tried all 3 power combinations. Everything worked.


      However, when I reviewed the source code for pd_hal_disable_vreg(), there is a comment that states:


      "If system has external VDDD source, internal VBUS regulator shall be turned off."


      I don't know if the comment is just a suggestion to save power, or will there be a conflict at an internal power node if I have both VDDD and VBUS_IN with internal VBUS regulator enabled.


      Can you please confirm if I have two separate sources for VDDD and VBUS_IN with internal VBUS regulator enabled? Just want to make sure there is no long-term negative effects even though this configuration is working for me.