The charged-device model (CDM) describes the discharge of an electrostatically charged component that comes into contact to a grounded conductive object. It assumes the discharge to be triggered by any pin of the component that comes into contact to the grounded object. In this connection, "pin" has to be understood as any metallic conductive surface of a component, which does not only include actual pins but e.g. also metallic heat slugs.
The CDM is especially important for the automated assembly of semiconductor components on printed circuit boards (PCB). It was developed in the course of the advancing automation in the 1980s and was first standardized in the mid 1990s. Today, the CDM is the most important discharge model on component level.