Folding circuit

摘要

A folding circuit includes a differential resistance ladder and a plurality of comparators coupled to the differential resistance ladder in a manner which substantially reduces capacitive loading on the differential ladder. In addition, the folding circuit has a minimum number of output resistors to facilitate resistor matching for precision outputs. In another aspect of the invention, the folding circuit has a replica gain matching circuit which includes a replica comparator of predetermined size, which is coupled to a replica differential ladder at a predetermined location so as to replicate the currents drawn by the comparators coupled to the main differential resistance ladder for precise gain matching.