This paper investigates the design principles of a solid-state circuit breaker (SS CB) for medium voltage direct current (MVDC) grids. The emphasis is given on the design of the required active and passive components that employed in a SS DCCB based on analytic methodology. Several cases related to the characteristics of the current technology of power semiconductor devices have been investigated and evaluated in terms of maximum short-circuit current, maximum switch current, maximum switch voltage, clearance time, as well as, passive elements requirements. It has been shown that potential improvements of the current power semiconductor technology could lead to improved performance of SS DCCB with lower requirements for passive elements. In particular, the most significant characteristic that improves the overall SS breaker performance was found to be a potential reduce of the falling time (or increase of power dissipation) of the switches used in SS breaker.