Author: ShifangZ_26 Version: **
Why is it mandatory to provide VBUS voltage to CCGx devices? How is it done in typical applications?
CCGx devices (except for CCG1, CCG2, and CCG4), in general have a VBUS_IN or a VBUS_MONITOR pin that must be connected to the VBUS input of the end application. The CCGx device firmware usually does not start its execution until the device detects the applied VBUS voltage. All actions that need to be taken by the Type-C port depend on the availability and value of the VBUS voltage supplied. The VBUS voltage is not only for VBUS Over Voltage Protection (OVP) and Under Voltage Protection (UVP) features, but also as an input for Port Policy Engine State transfer. This is independent of whether the end application that the customer is designing needs to have VBUS OVP/UVP features.
CCGx devices offer two ways to monitor the input VBUS voltage:
1. External Method (Outside CCGx chip).
Add a resistor divider network using a 100 kΩ 1% (or 10 kΩ 1%) and 10 kΩ 1% (or 1 kΩ 1%) on the VBUS signal and connect it to the default pin as listed in Table 1, or any available GPIO of the CCGx device as shown in Figure 1. It is recommended not to change the resistor divider ratio.
Figure 1. Resistor Divider Network for VBUS
This method is supported by the following CCGx devices: CCG1, CCG2, CCG3, CCG3PA, CCG4, CCG5, CCG6.
2. Internal Method (Internal to CCGx chip):
Some of the CCGx devices (CCG3, CCG3PA, CCG5, CCG6) have an integrated resistor divider network to monitor VBUS. The default pins that support this integrated resistor divider network of the respective CCGx device are listed in Table 1.
Table 1: List of CCGx Devices Supporting External/Internal Methods to Monitor VBUS
Default Pin Supported by CCGx Device
Pin#L4, Pin#B6 (96BGA)
Pin#13, Pin#37 (40QFN)
Pin#D1 Pin#L3 (96BGA)
Pin#A10, A11, B10, B11,
C10, C11, D10, D11,
E10, E11 (96QFN)
Thus, using one of the above methods, the CCGx firmware detects the VBUS voltage and initiates normal operation and firmware execution.