Ultra low voltage, low power 4-2 compressor for high speed multiplications

This paper presents a new low power 4-2 compressor capable of operating at an ultra-low voltage. Its merits are derived from a novel design of low-power XOR-XNOR gate at transistor level. The new circuit structure eliminates the weak logic on internal nodes in the XOR-XNOR module in contrast to the published designs. Driving capability has been considered in the design so that the 4-2 compressor cells can be used in the tree structured fast multiplier at low supply voltage. Simulation results show that the proposed 4-2 compressor is able to function at supply voltage as low as 0.6 V, and outperforms the conventional CMOS 4-2 compressor and variants of 4-2 compressor constructed with various combinations of recently reported superior low-power logic cells.