Research on Power Consumption Design Optimization of 4-Bit Absolute Value Comparator

Abstract

This paper conducts a systematic study on the optimized design of a 4-bit absolute value comparator, focusing on its critical role in digital circuits and exploring multi-dimensional performance enhancement approaches. First, the fundamental structure of the 4-bit absolute value comparator is elaborated, including the core functions of the absolute value generation module (which converts signed numbers into absolute values) and the comparison logic module (which performs magnitude comparison of absolute values).  Next, the research progress of existing optimization methods is reviewed: traditional CMOS designs achieve a balance between power consumption and delay through gate-level optimizations such as logic simplification and multi-threshold voltage (MTCMOS) techniques; adiabatic logic approaches (e.g., ECRL, PFAL) significantly reduce power consumption via energy recovery mechanisms but are limited by speed and power supply complexity; novel design strategies break through single-metric constraints by employing critical path restructuring, dynamic voltage scaling, and logic function reuse, thereby improving transmission rate, area efficiency, and reliability. Furthermore, the advantages and limitations of various methods are analyzed, including issues such as process sensitivity and scenario adaptability. Finally, the current research shortcomings and limitations are summarized, and targeted suggestions are proposed to provide a systematic reference for promoting the application of 4-bit absolute value comparators in low-power and high-performance scenarios.