US Patent 7298177 Method and mechanism to determine keeper size

A method and apparatus for determining the size of a keeper transistor in a dynamic circuit is provided. A first portion of a dynamic circuit, comprising the keeper transistor, is analyzed to determine keeper current data that describes what size the keeper transistor would need to be to supply a specified amount of keeper current. A second portion of the dynamic circuit is analyzed, separate from the first portion, to determine an estimated amount of leakage current that passes through the PDN when the PDN is not actively discharging the dynamic node may be determined. The size for the keeper transistor that enables the keeper transistor, when activated, to produce an amount of keeper current that is substantially equal to the estimated amount of leakage current may be determined based on the analysis performed on the first and second portion.