Low-Power Fanout Optimization Using Multi Threshold Voltages and Multi Channel Lengths

This paper addresses the problem of low-power fanout optimization for near-continuous-size inverter libraries. It is demonstrated that because of neglecting short-circuit current, previous techniques proposed to optimize the area of a fanout tree may result in excessive power consumption. This paper describes how the problem of low-power fanout optimization can be reduced to inverter-chain optimization problem and formulates the minimization of the total power consumption of an inverter chain as a geometric program. Moreover, it describes an efficient method to minimize the total power consumption of a fanout tree by using multiple-channel-length (multi-
L

_Gate
) and multiple-threshold-voltage (multi-
Vt
) techniques. Experimental results show that the proposed technique can reduce the power consumption of the fanout trees by an average of 11.17% over SIS fanout-optimization program.