INPUT TRACKING HIGH-LEVEL MULTIBIT QUANTIZER FOR DELTA-SIGMA ADC

摘要

A quantization circuit includes a plurality of resistors (R-0 to R-15), a plurality of tap points (16-3 to 16-15), and a plurality of coarse comparators (21-3 to 21-15). Each coarse comparator has a first input coupled to an input voltage (VSUBQin/SUB) and a second input coupled to a corresponding coarse tap point voltage. Each coarse comparator operates during a first phase to produce a "1 " only if the input voltage exceeds the corresponding coarse tap point voltage. A plurality of fine comparators (24-1 to 24-3) each have a first input coupled to the input voltage, and each fine comparator operates during a second phase to produce a fine output level indicative of whether the input voltage exceeds a corresponding tap point voltage of a group of tap points located immediately below the tap point connected to the highest coarse comparator producing a "1".