In this paper, new structures for digital code converter circuits in quantum dot cellular automata (QCA) technology are presented. The basic structure of most of these circuits is the XOR gate, which is widely used in digital design. Therefore, in the proposed, the XOR gate will be presented which will be better than previous circuits in terms of cell number and delay. Then, using the proposed circuits for the XOR gate, new circuits for generating parity bit, Binary to Gray, Gray to binary and BCD to gray code converter are introduced. Proposal designs have an efficient implementation in terms of complexity. The proposed structures are simulated using the QCAdesigner tool to evaluate the correct performance. The proposed final circuit as a digital code converter has improved by 37% in terms of cell consumption and 25% in speed.
