A 0.171-mW, 2.4-GHz Class-D VCO with dynamic supply voltage control

Abstract

A low-voltage, low-power class-D VCO is presented. An LDO based dynamic supply voltage control technique for the class-D VCO is proposed, which realizes fast and reliable start-up and extremely low-voltage operation of the class-D VCO. The proposed LDO-VCO is fabricated using a 28 nm CMOS technology. The measured phase noise is -115.9 dBc/Hz at 1 MHz offset from the 2.35 GHz carrier, while drawing the current of 760 μA from 0.5 V LDO input. The class-D VCO core consumes 0.171 mW from 225 mV LDO output and the FoM is 191.0 dBc/Hz.