Analysis and Optimization of Programmable Delay Elements for 2-Phase Bundled-Data Circuits

We present the design and analysis of three commonly used types of programmable delay elements suitable for use in 2-phase bundled-data asynchronous circuits. Our objective is to minimize power consumption and delay margins needed for correct operation under voltage scaling. We propose both circuit design and transistor sizing strategies to optimize these elements and discuss the relative trade-offs observed in a 65 nm bulk CMOS technology.