Analysis and design of oscillators based on low-voltage self-oscillating active inductors

This paper presents a new consistent analysis of self-oscillating active inductors together with a complete design example of a 90 nm CMOS current controlled oscillator (CCO) for ISM applications. Using the proposed passive compensation method in place of a standard negative impedance converter, typical performance of active inductor oscillator is achieved with reduced static power consumption. The article presents a small signal, large signal and phase noise analysis of the proposed oscillator together with related design trade-offs. Theoretical results are confirmed by a simulation of current controlled oscillator designed using UMC 90 nm 1P9M RF process libraries. The proposed circuit achieves a relative tuning range of 26% with a 434 MHz carrier frequency and average in band phase noise of -92 dBc/Hz at 1 MHz offset. The maximum power consumption of the oscillator core is only 2 mW from a 1 V supply.