The bus pins of the THVD1330 transceiver family include on-chip ESD protection against ±16-kV HBM and ±8-kV IEC 61000-4-2 contact discharge. The International Electrotechnical Commission (IEC) ESD test is far more severe than the HBM ESD test. The 50% higher charge capacitance, C_(S), and 78% lower discharge resistance, R_(D), of the IEC model produce significantly higher discharge currents than the HBM model.

Figure 9-2 HBM and IEC ESD Models and Currents in Comparison (HBM Values in Parenthesis)

The on-chip implementation of IEC ESD protection significantly increases the robustness of equipment. Common discharge events occur because of human contact with connectors and cables. Designers can choose to implement protection against longer duration transients, typically referred to as surge transients.