Yaser Nemati - Department of Computer Engineering, Beyza Branch, Islamic Azad University, Beyza, Iran
Nabiallah Shiri - Department of Electrical Engineering, College of Engineering, Shiraz Branch, Islamic Azad University,Shiraz, Iran,
Faramarz Samsami - Department of Computer Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran,

This paper proposed three different structures for ۴-Bit digital comparator. The structures have common andspecial features. These structures have been compared indifferent aspects such as power dissipation, number oftransistors, speed, etc. CMOS and pass-transistors technologyhave been used simultaneously in these three proposed highspeed structures. Simulations are performed by using Hspicebased on ۹۰nm CMOS technology, BSIM۴ (level ۵۴) version ۴.۴model. Finally, the best structure is proposed which is lowpower, high speed and using less transistors than the others.

Digital comparator, Pass transistor, Highspeed, Low power.