Switching region analysis for SOTB technology

Abstract

IoT (Internet of Things) devices tend to work intermittently, and the leakage power reduction in the sleeping state is essential. Although giving the reverse body bias to the back gate of transistors is an efficient technique to reduce the leakage power, it has not been commonly used dynamically because of the large timing overhead when a common CMOS process is used. However, recent SOI technologies enabled to use dynamic body bias control with an acceptable overhead. Here, we focus on Silicon On Thin Box (SOTB), a type of SOI technology which can control body biasing widely with a small overhead. For the dynamic body bias control, we analyzed timing overhead of a simple microcontroller and dynamically reconfigurable processor with SOTB technology. Evaluation results revealed that the sleep down time and the wake-up time are about hundreds microseconds both for the processor core, memory module, and smaller elements. We could not observe a certain relationship between the area of target modules and the timing overhead.