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Body channel communication (BCC) integrated circuits for emerging wireless body area network multimedia applications call for the need of high-speed inter-device data communication at ultra-low-power consumption and smaller device footprint. In this paper, a novel low-power injection-locking-based clock-recovery circuit (CRC) is proposed for BCC transceivers that employ multilevel direct digital signaling for high data rates. The CRC utilizes transition detection for generating pulses from transmitted digital data and injects them directly into the VCO to recover the clock. The pulse-based direct injection-locking architecture achieves instantaneous clock recovery from random multilevel data with a sensitivity of up to -43 dBm, and eliminates the need for a reference crystal used in conventional phase-locked-loop-based CRC circuits. Measured results verify that the proposed CRC achieves clock recovery for two- and three-level signals for data rates up to 160 Mb/s. Implemented in 65-nm CMOS technology, the CRC consumes 0.84 mW with a footprint of 0.12 \ mm^2. [ABSTRACT FROM AUTHOR]

Monitoring blood flow rate inside prosthetic vascular grafts enables an early detection of the graft degradation, followed by the timely intervention and prevention of the graft failure. This paper presents an inductively powered implantable blood flow sensor microsystem with bidirectional telemetry. The microsystem integrates silicon nanowire (SiNW) sensors with tunable piezoresistivity, an ultralow-power application-specific integrated circuit (ASIC), and two miniature coils that are coupled with a larger coil in an external monitoring unit to form a passive wireless link. Operating at 13.56-MHz carrier frequency, the implantable microsystem receives power and command from the external unit and backscatters digitized sensor readout through the coupling coils. The ASIC fabricated in 0.18-μm CMOS process occupies an active area of 1.5 × 1.78 mm^2 and consumes 21.6 μW only. The sensors based on the SiNW and diaphragm structure provide a gauge factor higher than 300 when a small negative tuning voltage (−0.5–0 V) is applied. The measured performance of the pressure sensor and ASIC has demonstrated 0.176 mmHg/√Hz sensing resolution. [ABSTRACT FROM PUBLISHER]