Superpositioning microactuator control and write current signals in a disc drive

An apparatus and method for reducing the number of interconnections in a disc drive through microactuator control and write current signal superpositioning. The disc drive includes a rotatable disc on which a plurality of tracks are defined and an actuator assembly supporting a read/write head having a write element. An actuator motor provides coarse (primary) positional control of the head and a microactuator disposed adjacent the head provides fine (secondary) positional control. A filter circuit is operably coupled between the write element and the microactuator and receives, by way of a common set of conductors, a combined signal comprising high frequency write current signals superimposed upon lower frequency microactuator control signals. The filter circuit filters the combined signal so as to pass the low frequency microactuator control signals to the microactuator and pass the high frequency write current signals to the write element.