HD3SS2522 Datasheet, PDF (11/25 Pages) Texas Instruments – USB Type-C SS MUX

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HD3SS2522
SLLSEM6B – APRIL 2015 – REVISED AUGUST 2015
7.3 Feature Description
7.3.1 Adaptive Common Mode Tracking for USB 3.1 MUX
The device provides an integrated USB 3.1 2:1 passive MUX. The MUX provides adaptive common mode
tracking allowing RX and TX channels to have different common mode voltage. This feature allows simpler
system implementation.
7.3.2 DFP-to-UFP Attach/Detach Detection
The HD3SS2522 monitors the CC lines as a Type-C DFP port. When the device senses that one of the CC has
a resistance to GND, it detects that an UFP is attached. The device provides an emulated ID signal (VBUS_EN)
in the event of a UFP attach.
The device also monitors specified pull down resistor according to Type-C specifications to determine if an active
cable is attached. In the event of active cable detection, HD3SS2522 provides necessary control signals for
VCONN switches that provide 5-V VCONN power to appropriate CC pin.
7.3.3 Plug Orientation/Cable Twist Detection
According to USB Type-C specifications plug can be inserted into a receptacle in either one of two orientations.
HD3SS2522 monitors for a pull-down resistors from an attached UFP port determining the MUX orientation.
7.3.4 VBUS Fault
HD3SS2522 does not take any action in case of a VBUS fault. VBUS fault needs to be handled by legacy power
management implementations.
7.3.5 VCONN Fault
If a VCONN fault is determined by the external power switch and fed into the device through VCONN_FAULT
pin, HD3SS2522 will latch it off until the cable is unplugged if there is a fault that does not clear within 5 ms.
Which is a sufficient amount of time to charge the 10-µF inrush capacitance.
7.4 Device Functional Modes
7.4.1 Unattached.DFP State
In this state, the HD3SS2522 as a DFP port is waiting to detect the presence of a UFP. The device injects pull-
up currents to both of the CC lines.
7.4.2 Attached.DFP State
When HD3SS2522 is in the Attached.DFP state, the port is attached and operating as a DFP. The device
continues to monitor the CC pins to make sure the appropriate pin is within vRd range specified by Type-C
specification. The device source current on one of the this CC pins and monitor its voltage. The port advertises
one of the three levels of VBUS power capability as specified in Type-C spec according to GPIO pins IMODE1
and IMODE2.
The device controls the VCONN power switches to apply VCONN to the unused CC pin if the voltage on the
unused CC pin is within the vRa range as specified in Type-C specification.
Copyright © 2015, Texas Instruments Incorporated
Product Folder Links: HD3SS2522
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