NXP Semiconductors' NX20P0477 is a single-chip USB-c (USB-c) port overvoltage protection solution with integrated moisture and corrosion protection algorithms. On the system side CC1 and CC2 pins are protected from 28 V short to V (bus). USB-C allows the V (bus) voltage to be increased up to 20 V through the power delivery protocol. Due to the mechanical twisting and sliding of the connector, the CC1 and CC2 pins can be shortened to V (bus) because the USB-C connector contact pins are 25% closer to each other than the micro USB connector. Moisture or fine dust can also cause the 20v V (bus) pin to short to adjacent pins.
The NX20P0477 makes the CC pin more robust even under abnormal conditions. The NX20P0477 is fault tolerant to 28v (DC) on the CON_CC pin of the connection side, and if the voltage is higher than the overvoltage threshold, it can quickly turn off the switch to protect the CC pin of the system side from the high voltage. The USB PD standard requires 80μ180μ, or 330μRp to detect sink devices, but this Rp currently accelerates the corrosion of contaminated water, especially seawater, when USB-C plugs the CC pins. Additionally, the CC/PD controller can identify this water impedance as a detected convergence, providing 5 V through the V (bus) pin, accelerating corrosion.
The NX20P0477 converts these usb standard Rp currents from CC/PD controllers to ultra low current sources to prevent corrosion. And integrates an IEC 61000-4-2 ESD protection +6 kV contact discharge and +8 kV air discharge on CON_CC1 and CON_CC2, which helps reduce external BOM cost. Also available in 0.5 mm pitch, nine bumps, and 1.49 mm x 1.49 mm x 0.555 mm WLCSP packages.
