Estimation of Iddq for early chip and technology design decisions

Quiescent chip current (Iddq) has been known for many years, but its role has changed in just the past few years from a valuable means to screen for reliability to a demon threatening to derail the industry´s phenomenal march of VLSI performance advances. Iddq originates with a phenomenon that is well-understood at the level of an individual transistor. However, at the chip level, both inter-chip and intra-chip process skew introduce wide and unexpected variation in Iddq. Despite these effects, meaningful predictions of Iddq can still be made at different points in the chip design cycle.