Design and Analysis of Low Power Comparator Using Switching Transistors

Abstract

Comparator is one of the fundamental building blocks in most analog to digital converters. Many high speed analog to digital converters such as flash analog to digital converter require high speed and low power comparators. A new double tail comparator is designed, where the circuit of a conventional double tail comparator is modified for low power and fast operation even in small supply voltages. Without complicating the design and by adding few transistors the positive feedback during the regeneration is strengthened which results in remarkably reduced delay time. Post layout simulation results in a 0.18μm technology confirm the analysis results. It is shown that in the switching transistors using dynamic comparator, both the power consumption and delay time are significantly reduced. Power consumption of conventional double tail comparator is 12μW in 0.8v and power is reduced to 9.5μW in double tail comparator using switching transistors with the same supply voltage.