Design of low power current starved VCO with improved frequency stability

Voltage Controlled Oscillator (VCO) plays a vital role in deciding the performance of VLSI circuits. Lot of research work is carried out on VCO from the past decades to achieve higher frequency, low power, low operating voltage, lower phase noise, and to increase tuning range. This paper mainly explores design of current starved voltage controlled ring oscillator for ultra low power applications. The performance comparison is done with respect to frequency stability and power consumption characteristics at 32nm technology node. Proposed C.S.D.T connection of VCO shows 48% higher speed at the cost of 18.9% increased power consumption over conventional VCO at V_DD = 0.4V. Furthermore, this paper explores effect of temperature variations on VCO performance. Proposed VCO shows less sensitivity to temperature variation over conventional VCO.