The optimum placement is close to the connector. EMI during an ESD event can couple from the tested trace to other nearby unprotected traces, which could result in system failures. The PCB designer must minimize the possibility of EMI coupling by keeping all unprotected traces away from protected traces between the TVS and the connector. Route the protected traces straight. Use rounded corners with the largest radii possible to eliminate any sharp corners on the protected traces between the TVS1801 and the connector. Electric fields tend to build up on corners, which could increase EMI coupling.

Ensure that the thermal pad on the layout is floating rather than grounded. Grounding the thermal pad will impede the operating range of the TVS1801, and can cause failures when the applied voltage is negative. A floating thermal pad allows the maximum operating range without sacrificing any transient performance.