Feedback-Switch Logic (FSL): A High-Speed Low-Power Differential Dynamic-Like Static CMOS Circuit Family

Charbel Akl and Magdy Bayoumi
university of louisiana at lafayette


We present a new dynamic-like static circuit family called Feedback-Switch Logic (FSL) that is suitable for high-speed low-power applications. FSL is a derivative of Cascode Voltage Switch Logic (CVSL) family. However, it does not suffer from the contention problems of clockless CVSL, and it consumes much less power than clocked CVSL (dual-rail domino). FSL gates offer fast switching, reduced capacitance, and input-switching dependent activity factor without the need of clock connection. An 18-bit majority voting circuit is simulated in a 90-nm technology, in order to compare static, clockless CVSL, dual-rail domino and FSL. Simulation results show that FSL reduces delay by 21% compared to static logic, and offers at least 46% power reduction compared to dynamic dual-rail domino logic with two-phase skew-tolerant clocking.