Voltage Controlled Ring Oscillator Design with Novel 3 Transistors XNOR/XOR Gates

In present work, improved designs for voltage controlled ring oscillators (VCO) using three transistors XNOR/XOR gates have been presented. Supply voltage has been varied from [1.8 1.2] V in proposed designs. In first method, the VCO design using three XNOR delay cells shows frequency variation of [1.900 0.964] GHz with [279.429 16.515] μW power consumption variation. VCO designed with five XNOR delay cells shows frequency variation of [1.152 0.575] GHz with varying power consumption of [465.715 27.526] μW. In the second method VCO having three XOR stages shows frequency variation [1.9176 1.029] GHz with power consumption variation from [296.393 19.051] μW. A five stage XOR based VCO design shows frequency variation [1.049 0.565] GHz with power consumption variation from [493.989 31.753] μW. Simulations have been performed by using SPICE based on TSMC 0.18μm CMOS technology. Power consumption and output frequency range of proposed VCOs have been compared with earlier reported circuits and proposed circuit’s shows improved performance.