A new conditional isolation technique (CI-Domino) in domino logic is proposed for wide domino gates. This technique can not only reduce the subthreshold and gate oxide leakage currents simultaneously without sacrificing circuit performance, but also it can be utilized to speed up the evaluation time of domino gate. Simulations on high fan-in domino OR gates with 0.18 µm process technology show that the proposed technique achieves reduction on total static power by 36%, dynamic power by 49.14%, and delay time by 60.27% compared to the conventional domino gate. Meanwhile, the proposed technique also gains about 48.14% improvement on leakage tolerance.

A new contention-free Domino logic (CF-Domino) that is especially suited for low threshold voltage (LVT) is reported. Its superior noise margin and speed over conventional Domino circuits for LVTs are demonstrated using HSPICE(R) simulations and a 0.25 µm CMOS technology with a supply voltage of 2.5 V. The impacts of the new technique on dynamic and leakage powers and area were evaluated. At a 3% area increase, and keeping the noise margins constant, the new CF-DOMINO achieves 20% less delay than conventional DOMINO as the threshold voltage scales from 450 mV down to 200 mV. It also achieved 13% less dynamic power and 5% less leakage at that threshold voltage.