Question: Why do we need a regulator and an auxiliary switch in Type-C to DisplayPort (DP) cable solution? Can we remove them?
The Type-C to DP cable solution is operated from either VBUS or VCONN voltage. VBUS will be at 5 V but VCONN can change from 2.7 V to 5.5 V. VBUS and VCONN voltages are logically ORed and fed to the LDO to get a stable 3.3 V, which will power the CCG1 device. Therefore, the LDO is very essential in the design and it cannot be removed.
An auxiliary switch in a Type-C to DP cable solution is required to switch the Sideband Use (SBU1 and SBU2) signals upon the successful entry of the DisplayPort Alternate mode. Having Auxiliary switch in this design is mandatory.