DP_IN and DM_IN protection consists of IEC ESD and overvoltage protection.

The DP_IN and DM_IN pins integrate an IEC ESD cell to provide ESD protection up to ±15-kV air discharge and ±8-kV contact discharge per IEC 61000-4-2 (for test conditions, see the ESD Ratings section). The IEC ESD performance of the TPS2584x-Q1 device depends on the capacitance connected from BUS pin to GND. TI recommends placing a A 0.22-µF capacitor close to the BUS pin

The ESD stress seen at DP_IN and DM_IN is impacted by many external factors like the parasitic resistance and inductance between ESD test points and the DP_IN and DM_IN pins. For air discharge, the temperature and humidity of the environment can cause some difference, so the IEC performance must always be verified in the end-application circuit.

Overvoltage protection (OVP) is provided for short-to-V_BUS or short-to-battery conditions in the vehicle harness, preventing damage to the upstream USB transceiver or hub. When the voltage on DP_IN or DM_IN exceeds 3.9 V (typical), the TPS25840-Q1 device immediately turns off DP/DM switch and responds to block the high-voltage reverse connection to DP_OUT and DM_OUT. FAULT signal asserts after 8-ms deglitch time. See Figure 11-30.

For DP_IN and DM_IN, when OVP is triggered, the device turns on an internal discharge path with 416-kΩ resistance to ground. On removal of the overvoltage condition, the pin automatically turns off this discharge path and returns to normal operation by turning on the previously affected analog switch.