Towards Energy-autonomous Integrated Systems Through Ultra-low Voltage Analog IC Design

In this paper, we bring an overview of main obstacles, limitations and challenges in design of ultra-low voltage analog integrated circuits in nanoscale technologies. Low-voltage and low-power circuits are designed using unconventional design techniques based either on non-standard devices and structures or new circuit topologies and transistors working in sub-threshold region. The low-voltage design methods and approaches will be described and evaluated. Then, examples of ultra-low voltage circuits designed in standard CMOS technology are presented. Finally, an experimental energy harvesting system for implantable medical devices using electromagnetic energy transfer through on-chip antenna, implemented in a standard CMOS process, is presented. This self-powered system employs several low-voltage and low-power circuits and blocks for voltage conversion and power management.