In VLSI applications, area, delay and power are the important factors which must be taken into account in the design of a fast adder. The paper attempts to examine the features of certain adder circuits which promise superior performance compared to existing circuits. The advantages of these circuits are low-power consumption, a high degree of regularity and simplicity. In this paper, the design of a 16-bit comparator is proposed. Magnitude comparison is one of the basic functions used for sorting in microprocessor and digital signal processing, so a high performance effective magnitude comparator is required.