Fast and compact dynamic ripple carry adder design

Adders are fundamental building blocks and often constitute part of the critical path. In this paper, we propose four high-speed ripple carry adder designs using dynamic circuit techniques. CMOS technology based SPICE simulations show that the proposed dynamic ripple carry adders are at least two times faster than the conventional static ripple carry adder. Further, all of the proposed designs compare much favorably to a previous dynamic ripple carry adder design that employs DCVS (differential cascode voltage switch) logic.