A DEM Structure Based on Random Combination Group Encoding toward a Reduced Circuit Area

The harmonic distortion is often caused by the nonlinearity inside digital-to-analog conversion, and the random rotation-based binary-weighted selection was proposed in previous work to ease the current source’s mismatch error. To reduce the complexity and the circuit area of the previous structure, a random combination grouping encoding-based dynamic-element matching structure is proposed as an improvement on the random rotation-based binary-weighted selection in this paper. By separating the rotation into several sub-rotation modules, the proposed structure divides the data input into groups to be encoded in parallel. The gate usage suggests that the proposed structure reduces resource consumption at the cost of the spurious-free dynamic range, where a loss no larger than 10 dBc is witnessed. Synthesis results present an area of 330.86 µm
²
with 5 bits of input operating at 1 GHz and an average reduction of 10% in the area is presented within the proposed grouping structure. The minimum clock cycle is decreased to 0.58 ns where the synthesis for the previous structure fails at this clock cycle.