Fault types

Fault conditions

Expected actions

Reverse current

CC output pin voltage exceeds

VCONN input voltage when the power

switch is turned off

The reverse biased body diode of the back- to-back MOS switches is

naturally disabled preventing current from flowing from CC output pin

to the input

Reverse voltage

CC output pin voltage exceeds

VCONN input voltage of more than

0.35 V for 5 V when the power switch

is turned on

Power switch is opened immediately until the voltage difference falls

below the voltage limit. I²C alert is asserted immediately thanks to

VCONN_SW_RVP_FAULT bits

3.5

High voltage protection

The STUSB1702 can be safely used in systems or connected to systems that handle high voltage on the VBUS

power path. The device integrates an internal circuitry on the CC pins that tolerates high voltages and ensures

protection up to 22 V in case of unexpected short-circuits with the VBUS or in the case of a connection to a device

supplying high voltage on the VBUS.

3.6

Hardware fault management

The STUSB1702 handles hardware fault conditions related to the device itself and to the VBUS power path during

system operation.

When such conditions occur, the circuit goes into a transient error recovery state named ErrorRecovery in the

Type-C FSM. In this state, the device de-asserts the VBUS power path by disabling the VBUS_EN_SRC pin and it

removes the terminations from the CC pins during several tens of milliseconds. Then, it goes to the unattached

source state.

The STUSB1702 goes into error recovery state when at least one condition listed below is met:

•

If an overtemperature is detected, the “THERMAL_FAULT” flag is asserted

•

If an internal pull-up voltage on the CC pins is below the UVLO threshold, the “VPU_VALID” flag is asserted

•

If an overvoltage is detected on the CC pins, the “VPU_OVP_FAULT” flag is asserted

•

If the VBUS voltage is out of the valid voltage range during attachment, the “VBUS_VALID” flag is asserted

•

If an undervoltage is detected on the VDD pin during attachment when UVLO detection is enabled, the

“VDD_UVLO_DISABLE” flag is asserted

•

If an overvoltage is detected on the VDD pin during attachment when OVLO detection is enabled, the

“VDD_OVLO_DISABLE” flag is asserted

The I²C register bits mentioned above give either the state of the hardware fault when it occurs or the setting

condition to detect the hardware fault.

3.7

Accessory mode detection

The STUSB1702 supports the detection of audio accessory mode and debug accessory mode as defined in the

USB Type-C standard specification with the following Type-C power modes (see Section 6 Start-up configuration):

•

Source power role with accessory support

3.7.1

Audio accessory mode detection

The STUSB1702 detects an audio accessory device when both CC1 and CC2 pins are pulled down to ground by

an Ra resistor from the connected device. The audio accessory detection is advertised through the

CC_ATTACHED_MODE bits of the I²C register CC_CONNECTION_STATUS.

3.7.2

Debug accessory mode detection

The STUSB1702 detects a connection to a debug and test system (DTS). The debug accessory detection is

advertised through the CC_ATTACHED_MODE bits of the I²C register CC_CONNECTION_STATUS.

•

In source power role, a debug accessory device is detected when both the CC1 and CC2 pins are pulled

down to ground by an Rd resistor from the connected device. The orientation detection is performed in two

STUSB1702

High voltage protection

DS12664 - Rev 1

page 12/38