A Fully-Digital 0.1-to-27 Mb/s ULV 450 MHz Transmitter with sub-100 $\mu \mathrm{W}$ Power Consumption for Body-Coupled Communication in 28 nm FD-SOI CMOS

A 0.5 V fully-digital 450 MHz transmitter for surface wave capacitive body-coupled communications is realized in 28 nm FD-SOI CMOS and consumes 17 to $76\ \mu \mathrm{W}$ for data rates from 0.1 to 27 Mb/s with up to 14% system efficiency. The heavily duty-cycled transmitter uses a 90 MHz free-running oscillator and edge combiners to generate OOK Gaussian-shaped pulses through a switched-capacitor PA. Body-biasing allows frequency tuning and adaptive efficiency optimization as a function of data rate.