A fast two-step coarse-fine calibration (CFC) technique for precision comparator design

A two-step offset correction technique for high precision comparator design is proposed. The two step coarse-fine calibration (CFC) technique provides precise offset correction much faster than a single step calibration and the circuit implementation is less complicated. The proposed two step calibration technique was employed on a two-stage dynamic latched comparator using 0.35μm CMOS process. The post layout simulations shows that the proposed technique improves the correction precision 15 times compared to a single stage offset correction while requiring less die area, correction cycles, and calibration time.