A semiconductor device includes an adjustable current source that is coupled to an external battery. The electrical connector includes an insulative housing, a number of contacts retained in the insulative housing, a metal shield covering the insulative housing, an insulative cover assembling outside of the metal shield, and a waterproof block interposed between the metal shield and the insulative cover along a vertical direction. An output of the attenuator controlled stage block is both slope and maximum voltage definable for a process independent design. The slider has one or more projections or ridges designed to impinge on a wall of a respective recess or throughhole opening in the zipper, thereby stopping the slider, provided that the pull off resistance is not overcome. Another power cord may be employed to facilitate recharging the battery through the auxiliary power source. A total volume V of the dimples is 300 mm3 to 700 mm3.