Abstract: A system providing an inductive power and data link between an external transmitter and miniature internal receiver is presented. The system is suited to applications where the receiver must be of a small size and the system must consume very little power, such as an implanted biomedical device. The system is also compatible with systems where bi-directional communications are required. The novel transmitter and receiver form an improved forward data telemetry system. The transmitter consists of a Class-E converter with its optimum operating frequency being synchronously, instantaneously and efficiently altered in accordance with the data to be transmitted, thereby producing an FSK modulated magnetic field of substantially constant amplitude. The constant amplitude output allows for the continuous, data-independent transfer of power to the miniature receiver and its associated electronics.