An apparatus for transcutaneously transmitting power and communication signals to an implantable device. The apparatus can include generators for power and information signals; receivers; and a coupler for independently coupling the power signal and a first information signal. An internal unit can have receivers for power and information signals; a second signal generator; and an independent coupler. The first and second information signal can be transmitted at a frequency greater than the power frequency. The external unit can also include a signal conditioner for symmetrically transceiving the first and second information signals; and an external data controller for symmetrically controlling the information signals. The internal unit can also include a voltage regulator converter; an internal signal conditioner for symmetrically transceiving the information signals; and a data controller. Symmetrically controlling can include ASK modulation of a data signal upon an RF carrier signal.