Power-Up Sequence Control for MTCMOS Designs

Power gating is effective for reducing standby leakage power as multi-threshold CMOS (MTCMOS) designs have become popular in the industry. However, a large inrush current and dynamic IR drop may occur when a circuit domain is powered up with MTCMOS switches. This could in turn lead to improper circuit operation. We propose a novel framework for generating a proper power-up sequence of the switches to control the inrush current of a power-gated domain while minimizing the power-up time and reducing the dynamic IR drop of the active domains. We also propose a configurable domino-delay circuit for implementing the sequence. Experimental results based on state-of-the-art industrial designs demonstrate the effectiveness of the proposed framework in limiting the inrush current, minimizing the power-up time, and reducing the dynamic IR drop. Results further confirm the efficiency of the framework in handling large-scale designs with more than 80 K power switches and 100 M transistors.