If the TVS2200 is in place to protect the device, during a surge event the voltage will rise to the breakdown of the diode at 25.9 V, and then the TVS2200 will turn on, shunting the surge current to ground. With the low dynamic resistance of the TVS2200, even large amounts of surge current will have minimal impact on the clamping voltage. The dynamic resistance of the TVS2200 is around 30 mΩ, which means 40 A of surge current will cause a voltage raise of 40 A × 30 mΩ = 1.2 V. Because the device turns on at 25.9 V, this means the input will be exposed to a maximum of 25.9 V + 1.2 V = 27.1 V during surge pulses, robustly protecting the USB Type-C port. This pulse is shown in Figure 9-2 and allows for robust protection of the circuit.

Finally, the small size of the device also improves fault protection by lowering the effect of fault current coupling onto neighboring traces. The small form factor of the TVS2200 allows the device to be placed extremely close to the input connector, lowering the length of the path fault current will take through the system compared to larger protection solutions.