Abstract: An improved high fan-in domino circuit is proposed.The nMOS pull-down network of the circuit is divided into several blocks to reduce the capacitance of the dynamic node and each block only needs a small keeper transistor to maintain the noise margin.Because we omit the footer transistor,the circuit has better performance than the standard domino circuit.A 64-input OR-gate implemented with the structure is simulated using HSPICE under typical conditions of 0.13μm CMOS technology.The average delay of the circuit is 63.9ps,the average power dissipation is 32.4μW,and the area is 115μm2.Compared to compound domino logic,the proposed circuit can reduce delay and power dissipation by 55% and 38%,respectively.

Key words: high fan-in, domino logic, high performance, keeper transistor