A 150mV-1.2V fully-integrated DC-DC converter for Thermal Energy Harvesting

A fully-integrated DC/DC converter for energy harvesting applications is presented. The startup-voltage of the converter is about 140mV, the output voltage exceeds 1.5V, with a power efficiency at least 20%. The architecture for boosting such extremely low voltages is based on an ultra-low-voltage oscillator cross connected to two phase charge pump. The overall circuit does not require any external components and can be fully integrated in a standard CMOS low voltage technology. A test-chip has been designed in UMC 0.18µm process.