Efficient data-directed scrambler for noise-shaping mixed-signal converters

An efficient data-directed scrambler is provided for processing digital signals having an unequally-weighted code. The data-directed scrambler includes inputs for receiving unequally-weighted bits of an input signal, outputs for supplying N scrambled bits of an output signal, and two or more scrambler columns connected in series between the inputs and the outputs. One or more of the scrambler columns includes a swapper cell and a digital fanout. Least significant bits in the unequally-weighted code are input to a swapper cell, and higher order bits in the unequally-weighted code are input to respective digital fanouts. In the other embodiments, an efficient data-directed scrambler is provided for processing digital signals having an equally-weighted code.