Analog-to-digital converter (ADC) having a folding stage and multiple ADC stages

摘要

An A/D converter including a folding stage and a plurality of conversion stages is described. The folding stage determines a sub-range in which an input analog voltage falls and adjusts the input analog voltage by a folding voltage offset corresponding to the determined sub-ranges to produce a residue voltage. Each following converter stage determines a voltage range in which the residue voltage falls. The converter stage multiplies the residue voltage by a factor of N to produce an intermediate voltage. The conversion stage selects a cyclic voltage offset corresponding to the sub-ranges in which the residue voltage falls and adjusts the intermediate voltage by the cyclic voltage offset to produce a new residue voltage.