USB Type-C port protector provides overvoltage and IEC ESD protection

15-06-2020 | Texas Instruments | Subs & Systems

Texas Instruments TPD4S311 USB Type-C Port Protector is a single-chip USB Type-C port protection device providing 20V Short-to-VBUS overvoltage and IEC ESD protection. Multiple accessories and products for USB Type-C have been released not meeting the USB Type-C specification. One example of this is USB Type-C PD adaptors that only put 20V on the VBUS line. Another concern for USB Type-C is mechanical twisting and sliding of the connector, which could short pins due to the near proximity they have in this small connector. This could cause 20V VBUS to be shorted to the CC and SBU pins. Also, due to the proximity of the pins in the Type-C connector, there is a raised concern that moisture and debris could cause the 20V VBUS pin to be shorted to the CC and SBU pins.

These non-ideal equipment and mechanical events make it essential for the CC and SBU pins to be 20V tolerant, even though the pins only function at 5V or lower. The device allows the CC and SBU pins to be 20V tolerant with no interference with normal operation by giving over-voltage protection on the CC and SBU pins. The device places high voltage FETs in series on the SBU and CC lines. When a voltage higher than the OVP threshold is identified on these lines, the high voltage switches are opened up, isolating the remainder of the system from the high voltage condition present on the connector.

Most systems need IEC 61000-4-2 system-level ESD protection for external pins. The device integrates IEC 61000-4-2 ESD protection for the CC1, CC2, SBU1, and SBU2 pins, removing the necessity to place high voltage TVS diodes externally on the connector.

Typical device applications include desktop PC/motherboards, standard notebook PCs, Chromebook and WOAs, docking stations, port/cable adapters and dongles, and smartphones.

By Natasha Shek