A Reference-Less Injection-Locked Clock-Recovery Scheme for Multilevel-Signaling-Based Wideband BCC Receivers

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 mm².