What, in simple terms, is the benefit of the KD1S topology?


Since 1-bit quantizers are used the transistor matching can be horrible.

Even the minor effects of the Kpath comparatorís offsets can be reduced

by adding a single pre-amp on the output of the integrator. Itís possible

to attain > 40 dB SNR (> 6-bits) with matching approaching 50 % (e.g.,

one transistors threshold at 100 mV while anotherís at 200 mV). This is

possible without calibrations or additional overhead. Considerably larger

SNRs can be achieved at the cost of conversion bandwidth.


While the KD1Sís tolerance to mismatches will clearly become more

important as CMOS technology marches toward the sub-10 nm nodes,

other benefits include: 1) the natural way the KD1S interfaces with

software for ease of changing the ADCís characteristics, 2) the higher-

sampling frequency, 3) itís small and low power, and 4) the design is

easy to move between process nodes.