A self-tuning digital telemetry IC for use in a microprocessor-based implantable instrument

An implantable digital telemetry integrated circuit that uses an automatic resonant-frequency search technique to adapt to antenna variations is presented. A VCO and an amplitude detector are used to search for the antenna's resonant frequency at the start of each transmission. The chip is designed to meet the communication requirements of a microprocessor-based telemetry system for the fast prototyping of implantable instruments for biomedical research applications. A full implementation of the telemetry IC, measuring 2.5 mm*2.9 mm, was fabricated in a 1.2 mu m low-voltage CMOS process and tested with good results.<
>