Design of quaternary 4-2 and 5-2 compressors for nanotechnology

Recently, Multiple Valued Logic (MVL) has attracted attention, because it reduces the area and complexity of circuits when compared to binary logic. Carbon nanotube field effect transistors (CNFET) are a good candidate for implementing MVL logic circuits, since determining the threshold voltage value of CNFET is easily achievable by changing the diameter of the nanotubes which are placed under the transistor gate. In this paper, quaternary CNFET based 4-2 and 5-2 compressor cells have been proposed. The proposed cell designs were investigated using HSPICE simulator with the standard 32 nm CNFET technology under different operational conditions such as different temperatures, different load capacitances, and different supply voltages. Also the sensitivity to process variations and noise immunity of the proposed designs have been investigated. The proposed quaternary logic designs reduce the delay of the multi operand addition of arithmetic circuits by eliminating the carry propagation overhead.