I have VCC used in different connectors. If I want to add ESD protection can I just add one near voltage regulator or should I add each one near the connectors? Thanks a lot!
Optimal placement of ESD suppressors begins at the location of ESD penetration into the system. This tactic reduces the ESD voltage and current initially experienced by the circuit and attenuates the ESD pulse that propagates past the ESD suppressor. Design as much practical space as possible between the ESD suppressor and the protected chip.
Placing an ESD suppressor too far away from the line it's protecting can reduce its effectiveness. The board trace inductance can cause an additional amount of voltage, or "overshoot," on the chip. To avoid this, install the ESD suppressor as close to the protected line as possible. The bottom line is that selecting an ESD "solution" is no longer as simple as choosing a suppressor that's rated for the operating voltage of the circuit. An effective solution now takes into account the layout of the circuit board, as well as the nonsuppression electrical characteristics of the ESD suppression devices. Before delving further into the specifics of ESD protection, it's helpful to review some fundamentals.