Low input voltage and high step-up integrated regulator for thermoelectric energy harvesting

This paper presents a low input voltage and high step-up fully integrated DC-DC regulator in 0.18 μm standard CMOS technology for thermoelectric micro-power generation. The circuit avoids off-chip components, non-standard processes, and is thus suitable for ultra-low voltage low profile system-on-chip applications. The proposed system can deliver a regulated output voltage of 1.5 V at 31 μW output power with an input voltage as low as 0.2 V. The maximum simulated efficiency is 22% at the given step-up range. The design methodology of an integrated inductor layout and oscillator has been reported in detail for the standard process. At the ultra-low voltage range of interest, the regulator is estimated to have lower cost, higher integration, and improved efficiency compared to the alternatives reported in literature, including the 90 nm and 0.18 μm two-stage charge pump designs previously reported by our team.