Redundant signed binary addition based digital-to-frequency converter

An accumulator-based digital-to-frequency (DFC) converter employing redundant signed binary addition (RSBA) is presented. RSBA is advantageous in that no carry propagation occurs resulting in constant delay regardless of operand word size. Utilising RSBA in the proposed DFC resolves the performance bottleneck in the DFC´s conventional implementation and achieves extremely high frequency resolution. In addition, a new RSBA-based 8:1 multiplexer is introduced for a complete RSBA implementation of the DFC. Experimental results show an increase of more than 3.5 times in the speed of the accumulator compared to the conventional implementation regardless of bit size of the adder.