Efficient Addition Circuits Using Three-Gate Reconfigurable Field Effect Transistors

Reconfigurable FETs (RFETs) are widely recognized as a promising way to overcome conventional CMOS architectures. This paper presents novel addition circuit intentionally designed to exploit the ability of RFETs to operate efficiently on demand as n- or p-type FETs. First, a novel Full Adder (FA) is proposed and characterized. A comparison with other designs shows that the proposed FA achieves a worst-case delay and a dynamic power consumption of up to 43.5% and 79% lower. As a drawback, in terms of the estimated area, it is up to 32% larger than the competitors. Then, the new FA is used to implement Ripple-Carry Adders (RCAs). A 32-bit adder designed as proposed herein reaches an energy–delay product (EDP) ~25.7× and ~141× lower than its CMOS and the RFET-based counterparts.