Compensation for Within-Die Variations in Dynamic Logic by using Body-Bias

Abstract — We propose a fine-grained scheme to compensate for within-die variations in dynamic logic to reduce the variation in leakage, delay and noise margin through body-biasing. We first show that the amount of body-bias compensation needed depends on the correlation that exists between gates, and then analytically show the possible reduction in the variance of the leakage of both a single and multiple dynamic logic gates. We then design a circuit to implement the system which provides the reduction in the variance of the leakage, delay and noise margin of dynamic logic gates and show that it produces a close match to the analytical results. In our design, the variance of a typical test circuit is reduced by 27 % and the variance of the path delay is reduced by 33%. I