A New Design of Low Power Asynchronous Comparator

The paper presents two types of asynchronous comparators, i.e. asynchronous ripple comparator and pre-end asynchronous comparator. Compared to synchronous comparator, the asynchronous ripple comparator reduces power as it doesn’t have to compare all bits of data. However, asynchronous ripple comparators still need to deliver the comparison results bit by bit. The power consumption of the comparator also increases as the number of bits increase. The other type is pre-end asynchronous comparators. This type of comparators improves the truth table of comparison operation to control the computation of every bit. Only when the higher bits are equal can the next lower bit be computed so that power consumption is significantly reduced. At the end of the paper, comparisons between power consumption by 5-bit, 8-bit, 16-bit and 32-bit synchronous comparators and synchronous comparators are made. Among them, the power consumed by 32-bit asynchronous comparator is only 20.0% as much as that by synchronous comparators.