§16§§This book discusses the design and implementation of energy harvesting systems targeting wearable devices. The authors describe in detail the different energy harvesting sources that can be utilized for powering low-power devices in general, focusing on the best candidates for wearable applications. Coverage also includes state-of-the-art interface circuits, which can be used to accept energy from harvesters and deliver it to a device in the most efficient way. Finally, the authors present power management circuits for using multiple energy harvesting sources at the same time to power devices and to enhance efficiency of the system.§§§§ §04§§Introduction.- Energy Harvesting Sources, Models and Circuits.- Interface Circuits for Thermoelectric Generator.- Zero Crossing Switching Control for L-based DC-DC Converters.- Polarity Mechanism for Thermoelectric Harvester.- Energy Combiner and Power Manager for Multi-Source Energy Harvesting.- References.- Index.§§§§ §04§hniques3.2.2.4 Startup Circuit3.2.3 Power Conversion Architectures3.2.4 System Robustness4 Zero Crossing Switching Control for L-based DC-DC Converters4.1 Background and Prior Work4.2 Example of ZCS Control Circuit4.2.1 Coarse/Fine ZCS Techniques4.3 Measurement Results5 Polarity Mechanism for Thermoelectric Harvester5.1 Prior Work in TEG Polarity Mechanism5.2 Example of Auto-Polarity Control Circuit5.2.1 Measurement Results of Auto-Polarity Circuits6 Energy Combiner and Power Manager for Multi-Source Energy Harvesting6.1 Reported Techniques in Energy Combiner Techniques6.2 Power Manager Implementation for Multi-Source Energy Harvesting6.2.1 Biomedical Processor6.2.2 Power Manager6.2.3 Sleep Mode OperationReferences