Table 7-3. Simplified Operation for OUT1 and OUT2

OUT1

OUT2

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H

H

Default Current in Unattached State

H

L

Default Current in Attached State

L

H

Medium Current (1.5 A) in Attached State

L

L

High Current (3.0 A) in Attached State

When operating in I2C mode, the TUSB320 device uses the SCL and SDA lines for clock and data and

the INT_N pin to communicate a change in I2C registers, or an interrupt, to the system. The INT_N pin is

pulled low when the TUSB320 device updates the registers with new information. The INT_N pin is open

drain. The INTERRUPT_STATUS register should be set when the INT_N pin is pulled low. To clear the

INTERRUPT_STATUS register, the end user writes to I2C.

When operating in GPIO mode, the OUT3 pin is used in place of the INT_N pin to determine if an audio

accessory is detected and attached. The OUT3 pin is pulled low when an audio accessory is detected.

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 may back power the device.

7.3.5 VBUS Detection

The TUSB320 device supports VBUS detection according to the Type-C specification. VBUS detection is used to

determine the attachment and detachment of an 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 TUSB320

device if the PORT pin is configured as a DRP or an UFP. If the TUSB320 device is configured as a DFP and

only ever used in DFP mode, the VBUS_DET pin can be left unconnected.

7.4 Device Functional Modes

The TUSB320 device has four functional modes. Table 7-4 lists these modes:

Table 7-4. USB Type-C States According to TUSB320 Functional Modes

MODES

GENERAL BEHAVIOR

PORT PIN

STATES(1)

Unattached

USB port unattached. ID, PORT

operational. I2C on. CC pins

configure according to PORT pin.

UFP

Unattached.SNK

AttachWait.SNK

DRP

Toggle Unattached.SNK → Unattached.SRC

AttachedWait.SRC or AttachedWait.SNK

DFP

Unattached.SRC

AttachWait.SRC

Active

USB port attached. All GPIOs

operational. I2C on.

UFP

Attached.SNK

DRP

Attached.SNK

Attached.SRC

Audio accessory

Debug accessory

DFP

Attached.SRC

Audio accessory

Debug accessory

Dead battery

No operation.

VDD not available.

UFP/DRP/DFP

Default device state to UFP/SNK with Rd.

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TUSB320, TUSB320I

SLLSEN9F – MAY 2015 – REVISED MARCH 2022

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