A Domino Circuit Technique for Noise-Immune High Fan-In Gates

Abstract

Noise immunity is an important concern in deep nano-scale technologies, especially for high fan-in gates. In this paper, a new domino circuit technique is proposed by which the noise immunity of high fan-in gates increases while the power consumption reduces. The proposed technique is based on the comparison of two currents, which vary with respect to the voltage across the pull-down network (PDN). By comparing these currents, the voltage level of the dynamic node is pulled up or pulled down depending on the input voltages. Using this technique, the voltage swing on the PDN can be decreased to reduce the power consumption. Moreover, a diode-connected NMOS transistor is added in series with the PDN in the proposed technique. This will result in reducing the subthreshold leakage current due to the stacking effect and, as a result, the noise immunity will improve. To demonstrate the efficacy of the proposed domino design over the conventional techniques, high fan-in gates are designed and compared in 90[Formula: see text]nm CMOS technology. Simulation results exhibit at least 1.87X noise immunity improvement and 20% power consumption reduction in comparison to the standard footless domino (SFLD) circuits at the same delay.