HVDA551 and HVDA553 families come with high on-chip IEC ESD protection, but if higher levels are desired, external TVS diodes can be used. TVS diodes and bus-filtering capacitors must be placed as close as possible to board connectors to prevent noisy transient events into PCB. Placement at the connector also prevents these harsh transient events from propagating further into the PCB and system. Use VCC and ground planes to provide low inductances. High frequency current follows the path of least impedance and not the path of least resistance. TI recommends designing the bus protection components in the direction of the signal path. Do not force transient current to divert from signal path to reach protection device.
High-frequency currents follows the path of least impedance and not the path of least resistance.