In this paper authors have design the High Speed Power Efficient CMOS Voltage Comparator which can be realized in A/D Converters. The simulation is carried out in 130nm and 90nm technologies. The supply voltage for this comparator is 1v and 0.9v for 130nm and 90nm respectively. The Characterization of comparator is done in terms of offset, ICMR, propagation delay, power dissipation in both the technologies and the result has been compared for both the technologies. The simulation results shows that the speed of 1.92GHz and 2.44GHz with the power dissipation of 9.19µW and 7.45µW was achieved in 130nm and 90nm technologies respectively.