NXP's USB Type-C CC provides an intelligent anti-corrosion solution for low current sources

     NX20P0477 is a USB-c (Type-C) interface overvoltage protection solution integrated with anti-damp corrosion algorithm. The CC1/CC2 pins on the system side prevent short conversion of 28v VBUS. USB-C allows the VBUS voltage to be increased to 20 V over the power transfer protocol. Due to the mechanical twisting and sliding of the connectors, the CC1/2 pins can be shortened to VBUS because the USB-c connectors touch the pins 25% closer to each other than the micro-USB connectors.

     Humidity or fine dust may also cause 20v VBUS pins to be short to adjacent pins. NX20P0477 makes CC pins more robust in abnormal situations. The NX20P0477 has a 28v DC tolerance on the CON_CC pin on the connector side to quickly disconnect the switch if the voltage exceeds the overvoltage threshold, protecting the CC pin on the system side from high voltage. The USB PD standard requires 80 μA, 180 μA, or 330 μA as Rp to detect sinking devices, but this Rp current can accelerate corrosion of the USB-C connector pins when the CC pins are contaminated with water, especially salt water.

     In addition, the CC/PD controller can recognize this water impedance as a detected sink, providing 5 V via the VBUS pin, thus accelerating corrosion. NX20P0477 converts these USB standard Rp currents from CC/PD controllers to ultra-low current sources to prevent corrosion. NX20P0477 integrates ESD protection for IEC 61000-4-2 + 6kv contact discharge and + 8kv air discharge on CON_CC1 and CON_CC2, helping to reduce external BOM costs. The NX20P0477 CON_CC1 and CON_CC2 pins are designed to protect against surge voltages up to +/- 40v. The NX20P0477 is offered in a 0.5mm pitch, 9 bumps, and 1.49mm x 1.49mm x 0.555mm WLCSP package.