Analytical Estimation of Path-Delay Variation for Multi-Threshold CMOS Circuits

Shiho HAGIWARA  Takashi SATO  Kazuya MASU  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E92-A   No.4   pp.1031-1038
Publication Date: 2009/04/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E92.A.1031
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Advanced Technologies Emerging Mainly from the 21st Workshop on Circuits and Systems in Karuizawa)
Category: 
Keyword: 
device parameter variation,  MTCMOS,  timing analysis,  Monte-Carlo simulation,  

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Summary: 
Circuits utilizing advanced process technologies have to correctly account for device parameter variation to optimize its performance. In this paper, analytical formulas for evaluating path delay variation of Multi-Threshold CMOS (MTCMOS) circuits are proposed. The proposed formulas express path delay and its variation as functions of process parameters that are determined by fabrication technology (threshold voltage, carrier mobility, etc.) and the circuit parameters that are determined by circuit structure (equivalent load capacitance and the concurrently switching gates). Two procedures to obtain the circuit parameter sets necessary in the calculation of the proposed formulas are also defined. With the proposed formulas, calculation time of a path delay variation becomes three orders faster than that of Monte-Carlo simulation. The proposed formulas are suitably applied for efficient design of MTCMOS circuits considering process variation.