High input range sense comparator for multilevel Flash memories

This paper presents the experimental evaluation of a fully-differential offset-compensated voltage comparator designed for use in multilevel (ML) Flash memory sensing. The comparator is made up by an input buffering stage followed by a gain stage that performs a regenerative action. The input stage, which must provide high input common mode range, is powered by a high-voltage supply V/sub PP/, while the gain stage is operated from the standard supply V/sub DD/, thus limiting current drawing from V/sub PP/. The circuit has been integrated in a 0.13-/spl mu/m triple-well Flash CMOS process. The experimental evaluation showed an overall comparison time of 35 ns with an input signal of 10 mV and a current consumption of 15 /spl mu/A from V/sub PP/. These results make the proposed solution well suited for ML sensing.