Patent ID: 6060925
Filing Date: 2000-05-09
Classification: H03K

Abstract:
A Schmitt-trigger circuit that consumes less power by reducing an amount of a required DC (Direct Current) current, wherein said circuit comprises:comparison means responsive to an input signal for generating an output signal, wherein said comparison means comprises:a first MOS (Metal-Oxide-Semiconductor) transistor having a gate, a drain, and a source, said source of said first MOS transistor being coupled with a first reference voltage potential;a second MOS transistor having a gate, a drain, and a source, said source of said second MOS transistor being coupled with a second reference voltage potential;a third MOS transistor having a gate, a drain, and a source, said drain of said third MOS transistor being coupled with said drain of said second MOS transistor for generating said output signal, said gate of said third MOS transistor being coupled with said gate of said first MOS transistor, and said gate of said second MOS transistor for receiving said input signal; anda first feedback MOS transistor having a gate, a drain, and a source, said drain of said first feedback MOS transistor being coupled with said source of said third MOS transistor, said source of said first feedback MOS transistor being coupled with said drain of said first MOS transistor, said gate of said first feedback MOS transistor being used to receive said feedback signal to cut said current path inside said comparison means when said voltage level of said input signal rises to a lower trigger point of said predetermined threshold; andcurrent cutting means responsive to said output signal and said input signal for generating a feedback signal to cut a current path inside said comparison means when a variation of a voltage level of said input signal is higher than a predetermined threshold.