Research on CDM Peak Current of High Speed Pins Based on 2.5D and 2D Package

The trend and principle of the change of CDM peak current of IO high speed pin with pin position in 2.5D and 2D packages are analyzed in this paper. The CDM peak current value depends on the total charge and Td. Based on the results, the total discharge charge of the IO pin is insensitive to the pin position, and Td increases as the pin position moves away from the package center. This is related to parasitic parameters in the discharge path, the larger the package parasitic parameters of the pins, the longer discharge time and therefore the lower the corresponding CDM peak current. Therefore, the influence of pin position should be fully considered in the CDM current design, especially for the high-speed IO pins that are sensitive to CDM current.