Integrated power controllers and RF data transmitters for totally implantable telemetry

Data transmitters and power/source controllers are common elements in all totally implantable instrumentation systems. Two custom-designed integrated circuits have been developed for these elements and have significant impact on the realization of compact reliable telemetry packages. The first is an elapsed-time power switch that can remotely turn on implanted battery-powered systems with a short RF burst; to prevent accidental battery drainage, it will automatically turn off after a preprogrammed time (1-5 min). The second is a precision RF transmitter capable of operation up to 125 MHz in either FM or pulse-coded format and requires only two nonintegrated inductors. These IC systems are basic building blocks for a large number of totally implantable telemetry applications.