Inherent Charge-Sharing-Free Dynamic Logic Gates Employing Transistors With Multiple Independent Inputs

Abstract

Charge sharing poses a fundamental problem in the design of dynamic logic gates, which is nearly as old as digital circuit design itself. Although, many solutions are known, up to now most of them add additional complexity to a given circuit and require careful optimization of device sizes. Here we propose a simple CMOS-technology compatible transistor level solution to the charge sharing problem, employing a new class of field effect transistors with multiple independent gates (MIGFETs). Based on mixed-mode simulations in a coordinated device-circuit co-design framework, we show that their underlying device physics provides an inherent suppression of the charge sharing effect. Circuit layouts and design examples are discussed, which elucidate the fundamental differences in circuit topology to classical CMOS designs. For example it is shown that dynamic gates from MIGFET scale much better with stack height of long serial networks, leading to an increased circuit performance, while also providing higher signal stability.

Keywords

• Dynamic logic gates
• charge sharing
• domino logic
• reconfigurable transistor
• Schottky transistors
• multigate