Analysis of the Influence of Package Size and Pin Type on CDM Peak Current

The influence of large package size and pin types on CDM peak current is analyzed in this paper. The study reveals that as the package size increases, the CDM peak current continues to rise. Moreover, for different package sizes, the CDM peak current of IO (Input/Output, e.g., RX and TX) pins is consistently lower than that of PG (Power and Ground) pins, indicating that the CDM protection capability of IO pins is weaker than that of PG pins. This is mainly attributed to the higher parasitic resistance of IO pins, resulting in a longer discharge time compared to PG pins, and the accumulated charge on IO pins is less than that on PG pins. This paper can provide design guidelines for CDM considerations across different package sizes and pin types, particularly for large package dimensions and high-speed pins, thereby enhancing the robustness of CDM design.