Why Is It Mandatory to Provide VBUS Voltage for CCGx Devices – KBA229727

Version 3

    Author: ShifangZ_26           Version: **

     

    Translation - Japanese: CCGxデバイスへVBUS電圧の供給が必須な理由を教えてください。一般的なアプリケーションではどのように行われますか?– KBA229727 - Community Translated (JA)

     

    Question:

    Why is it mandatory to provide VBUS voltage to CCGx devices? How is it done in typical applications?

     

    Answer:

    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

     

    CCGx

    External Method

    Internal Method

    Default Pin Supported by CCGx Device

    CCG1

    Yes

    No

    Pin#35 (40QFN)

    Pin#C4 (35WCSP)

    CCG2

    Yes

    No

    Pin#17 (24QFN)

    CCG3

    Yes

    Yes

    Pin#B1 (42CSP)

    Pin#25 (32QFN)

    Pin#31 (40QFN)

    CCG3PA

    Yes

    Yes

    VBUS_IN_DISCHARGE

    VBUS_C_DISCHARGE

    CCG4

    Yes

    No

    Pin#3 (24QFN)

    Pin#L4, Pin#B6 (96BGA)

    Pin#13, Pin#37 (40QFN)

    CCG5/5C

    Yes

    Yes

    Pin#22 (40QFN)

    Pin#D1 Pin#L3 (96BGA)

    CCG6

    Yes

    Yes

    Pin#22 (40QFN)

    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.