An implantable digital telemetry integrated circuit using an automatic resonant-frequency search technique

An integrated circuit is presented which uses a voltage-controlled oscillator (VCO) and amplitude detector to search for the resonant frequency prior to each transmission, thus guaranteeing resonant operation despite variations in either antenna or integrated circuit characteristics. A block diagram of the transmitter is shown. The transmitter design is combined with a simpler on-off keying receiver and the necessary digital logic to support bidirectional digital telemetry.<
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