A 350-mV 2.4GHz Quadrature Oscillator with Nearly Instantaneous Start-Up Using Series LC Tanks

Abstract

We propose a ring-based quadrature LC-tank oscillator for Internet-of-Things (IoT) that can operate under a 350-mV supply voltage of energy harvesters. The oscillator is based on a series LC tank, with additional control circuitry to realize a nearly instantaneous start-up of one/two RF cycles to facilitate a deeply duty-cycled burst-mode operation of IoT. Fabricated in TSMC 28nm CMOS, the prototype consumes less than 1.3mW from 350mV supply and 0.07mm2 in area, while achieving phase noise of better than −118dBc/Hz @3MHz. Frequency tuning range is 2.24∼2.61GHz