Note

When using the 3.3-V supply for I2C, the end user must ensure that the VDD is 3 V and above.

Otherwise the I2C can back power the device.

6.3.6 VBUS Detection

The TUSB322I device supports VBUS detection according to the Type-C Specification. VBUS detection is used

to determine the attachment and detachment of a UFP and to determine the entering and exiting of accessary

modes. VBUS detection is also used to successfully resolve the role in DRP mode.

The system VBUS voltage must be routed through a 900-kΩ resistor to the VBUS_DET pin on the TUSB322I

device.

6.3.7 Cable Orientation and External MUX Control

The TUSB322I device has the ability to control an external/discrete MUX using the DIR pin. The TUSB322I

detects the cable orientation by monitoring the voltage on the CC pins. When a voltage level within the proper

threshold is detected on CC1, the DIR pin is pulled low. When a voltage level within the proper threshold is

detected on CC2, the DIR is pulled high. The DIR pin is an open drain output. The I2C communicates the cable

orientation status for the TUSB322I device.

6.3.8 VCONN Support for Active Cables

The TUSB322I device supplies VCONN to active cables when configured in DFP mode or in DRP acting as a

DFP mode. VCONN is provided only when the unconnected CC pin is terminated to a resistance, Ra, and after a

UFP is detected and the Attached.SRC state is entered. When in DFP mode or in DRP acting as a DFP mode, a

5-V source must be connected to the VDD pin of the TUSB322I device after Attached.SRC. VCONN is supplied

from VDD through a low resistance power FET out to the unconnected CC pin. VCONN is removed when a

detach event is detected and the active cable is removed.

6.4 Device Functional Modes

The TUSB322I device has four functional modes. Table 6-4 lists these modes:

Table 6-4. USB Type-C States According to TUSB322I Functional Modes

MODES

GENERAL BEHAVIOR

MODE

STATES(1)

Unattached

USB port unattached. ID, PORT

operational. I2C on.

UFP-Only

Unattached.SNK

AttachWait.SNK

DRP

Toggle Unattached.SNK → Unattached.SRC

AttachedWait.SRC or AttachedWait.SNK

DFP-Only

Unattached.SRC

AttachWait.SRC

Active

USB port attached. All GPIOs

operational. I2C on.

UFP-Only

Attached.SNK

Audio Accessory

Debug Accessory

DRP

Attached.SNK

Attached.SRC

Audio accessory

Debug accessory

DFP-Only

Attached.SRC

Audio accessory

Debug accessory

Dead battery

No operation.

VDD not available.

DRP

Default device state to UFP/SNK with Rd.

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TUSB322I

SLLSEO5D – OCTOBER 2015 – REVISED MARCH 2021

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Product Folder Links: TUSB322I