A Quaternary Half-Adder Using Current-Mode Operation with Bipolar Transistors

In this work some Multi-Valued Logic (MVL) blocks are initially presented and they will be used to the final building of a Quaternary half-adder. A circuit equivalent to an Exclusive-OR binary gate from the binary world but working for the quaternary world is performed. Also, other basic gates are necessary like the shifter circuit, equivalent to the Not gate of the binary world, and the switching block, a core for the circuits here presented. All the circuits are built with bipolar transistors operating in current-mode.