Clock Controlled Dual keeper Domino logic structures (CCDD_1 and CCDD_2) for achieving a high‐speed performance with low power consumption and a good noise margin are proposed in this paper. The keeper control circuit comprises an additional PMOS keeper transistor controlled by the clock and foot node voltage. This control mechanism offers abrupt conditional control of the keeper circuit and reduces the contention current, leading to high‐speed performance. The keeper transistor arrangement also reduces the loop gain associated with the feedback circuitry. Hence, the circuits offer less delay variability. The design and simulation of various wide fan‐in designs using 180 nm CMOS technology validates the proposed CCDD_1 and CCDD_2 designs, offering an increased speed performance of 7.2% and 8.5%, respectively, over a conventional domino logic structure. The noise gain margin analysis proves good robustness of the CCDD structures when compared with a conventional domino logic circuit configuration. A Monte Carlo simulation for 2,000 runs under statistical process variations demonstrates that the proposed CCDD circuits offer a significantly reduced delay variability factor.

Precise keeper control of domino logic circuit can significantly increase the speed of operation. However, the positive feedback gain associated with the feedback keeper circuit unduly increases the delay variability. Here, a novel high-speed clock delayed dual keeper (CDDK) domino circuit is presented, which aims at reducing the delay and lower the impact of loop gain on delay variability. In CDDK domino structure, the keeper circuit comprising of two keeper devices is disabled during the initial evaluation phase. This significantly reduces the contention current and thereby the operating speed of the circuit is enhanced. The simulations of the circuits have been carried out for various metrics and the results have been analysed. Furthermore, the Monte-Carlo simulations carried out for 2000 runs on a 128-input OR gate using CDDK structure demonstrate reduced delay variability characteristics due to smaller loop gain of the CDDK domino structure against the conventional domino logic style. The enhanced speed of operation due to reduced contention current is demonstrated. The results are validated through comparison against the conventional domino logic counterpart circuits. The analyses of the circuits are performed using industry standard full-suite Cadence® tools using 90 nm technology library.

No abstract

No abstract

This paper presents a novel energy efficient logic called Charge Sharing Improved Pass Gate Adiabatic Logic (CSIPGL) operating using four phase power clock sources. The CSIPGL based circuit is capable of operating through a wider range of frequency from 100MHz to 1GHz. CSIPGL logic has been designed using UMC 90nm technology model files and are simulated using Cadence® Virtuoso EDA tools. Efficiency of CSIPGL circuit is validated by comparing it against CSSAL, SQAL, SyAL, adiabatic logic circuits based on single charge sharing transistor [14] and EE-SPFAL circuit designs. Power consumption of AND/NAND and XOR/XNOR sub modules used in the design of 4-bit Carry Lookahead Adder circuits (CLA) are compared. 4-bit CLA is taken as a benchmark circuit to validate the efficiency of the proposed CSCPAL circuit.