Low-Power Clocked-Pseudo-NMOS Flip-Flop for Level Conversion in Dual Supply Systems

Clustered voltage scaling (CVS) is an effective way to decrease power dissipation. One of the design challenges is the design of an efficient level converter with fewer power and delay overheads. In this paper, level-shifting flip-flop topologies are investigated. Different level-shifting schemes are analyzed and classified into groups: differential style, n-type metal-oxide-semiconductor (NMOS) pass-transistor style, and precharged style. An efficient level-shifting scheme, the clocked-pseudo-NMOS (CPN) level conversion scheme, is presented. One novel level conversion flip-flop (CPN-LCFF) is proposed, which combines the conditional discharge technique and pseudo-NMOS technique. In view of power and delay, the new CPN-LCFF outperforms previous LCFF by over 8% and 15.6%, respectively.