A fully-integrated low-power BPSK based wireless inductive link for implantable medical devices

During the past decades, research has progressed on the biomedical implantable electronic devices that require power and data communication through a wireless inductive link. In this paper, we present a fully integrated binary phase-shift-keying (BPSK) demodulator based on a hard-limited COSTAS loop topology. The demodulator features with a data transmission rate of 1.12 Mbps and consumes less than 0.5 mW under a supply voltage of 1.8 V, which has been implemented in a CMOS 0.18 μm technology. In addition, the employment of BPSK demodulation combined with a passive modulation method allows full-duplex data communication between an external controller and the implant device, which may improve the controllability and observability of the whole implanted system.