Current-mode level restoration: circuit for multi-valued logic - Electronics Letters

Introduction: The multi-valued logic (MVL) is an alternative to common binary logic. The arithmetic operations can be performed more efficiently, and faster, by increasing the radix of the system or the number of levels used, at the expense of reduced noise margin. Thus, it suffers from noise and parameter variations. Since the variations at each stage are added up, it is unavoidable to restore the tabulated levels after a certain number of stages, unless the gates are self restored types [1]. In this Letter a new full-current-mode CMOS-MVL restoration circuit is presented. In an MVL system, the radix, r, corresponds to the number of discrete values or number of possible signal levels. In current mode, levels are represented by current levels in terms of a base current, Ib. The base current is set to 10 mA for this study. Thus, MVL variable x1⁄4 0 is associated with the current value, l0, of null, x1⁄4 1 is associated with l11⁄4 Ib1⁄4 10 mA and so on. However, in the circuits, a logic current level, l, actually corresponds to an interval of the continuous quantity y, such that