General description

NX20P0477 is a single-chip USB Type-C (USB-C) port overvoltage protection solution

integrating a corrosion prevention algorithm from moisture. CC1/CC2 pins in the system

side are protected from 28 V short to VBUS.

USB-C allows VBUS voltage to increase up to 20 V through Power delivery protocol.

CC1/2 pins can be shorted to VBUS due to mechanical twisting and sliding of the

connector since USB-C connector contact pins are 25 closer to each other than a

micro USB connector. Moisture or fine dust may also cause the 20 V VBUS pin to be

shorted to adjacent pins.

NX20P0477 enables CC pins to be more robust in even abnormal conditions.

NX20P0477 is 28 V DC tolerant on CON_CC pins in connector side and quickly

disconnects switches if the voltage is above overvoltage threshold, protecting CC pins in

system side from high voltage.

USB PD standard requires 80 μA, 180 μA or 330 μA as Rp to detect sink device, but this

Rp current accelerates USB-C connector pin corrosion when CC pins are contaminated

with water, especially salt water. Furthermore, CC/PD controller may recognize this water

impedance as detected sink, providing 5 V through VBUS pin, which accelerates

corrosion.

NX20P0477 converts these USB standard Rp currents from CC/PD controller to ultra-low

current source to prevent corrosion.

NX20P0477 integrates IEC 61000-4-2 ESD protection of +6 kV contact discharge and

+8 kV air discharge on CON_CC1 and CON_CC2, which helps to reduce external BOM

cost. NX20P0477 CON_CC1 and CON_CC2 pins are designed to be protected from surge

voltage up to +/-40 V. NX20P0477 is offered with 0.5 mm pitch, 9 bumps, 1.49 mm x 1.49 mm x 0.555 mm WLCSP package.

Features and benefits

• USB Type-C CC1 and CC2 short protection to VBUS

• CON_CC1 / CON_CC2: 28VDC AMR

• Rd clamp circuit in CON_CC1/CON_CC2 in dead battery condition

• Smart corrosion prevention scheme with low current source

• 250 mΩ Low RDSon switch

• Robust ESD immunity for CON_CC1/CON_CC2

– IEC 61000-4-2 contact discharge: 6 kV

– IEC 61000-4-2 air discharge: 8 kV

• +/-40 V surge protection on CON_CC1/CON_CC2

• Low leakage current: 14 μA

• CC1 / CC2 leakage current: < 1 μA

• Fast OVP turn-off time: 60 ns

Applications

• Smartphone

• Tablet

• Laptop