Effects of TVS integration on system level ESD robustness

Higher integration of Transient Voltage Suppression (TVS) functionality into ASIC I/O cells implies lower system costs. But as the ESD pulse is directed deeper into the system, migrating the TVS clamping function from the periphery of the system to a central ASIC may actually reduce the system´s ESD robustness. ESD current reconstruction scanning can be used to trace the current path on a PCB, and possibly within an IC. The article compares the current spreading during and ESD for different ESD protection methods.