A low energy crystal-less double-FSK transceiver for wireless body-area-network

An energy-efficient crystal-less double-FSK transceiver for wireless body-area-network (WBAN) is implemented in 0.18 μm CMOS technology with 1 V supply. The injection-locking digitally-controlled oscillator (IL-DCO) replaces the crystal oscillator (XO), which leads to reduce energy consumption and system cost. It can detect whether injection locking occurs or not, and calibrates the frequency drift of DCO within 100 kHz accuracy over 100 degrees C temperature variation. The scalable divider-based double-FSK transmitter eliminates the necessity of power-consuming voltage-controlled oscillator (VCO) and direct digital synthesizer (DDS). The frequency calibration with IL-DCO and transmitter consumes 1 mW and 2 mW, respectively, with a data rate of 10 Mb/s, corresponding to energy consumption of 0.2 nJ per transmitted bit.