doc.: IEEE q Submission Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Energy Harvesting Use Cases] Date Submitted: [March 19 th, 2013] Source: [Reghu Rajan] Company [Microsemi] Address [15822 Bernardo Center Dr, Ste B, San Diego, CA, 92127] Voice:[ ] FAX :[ ] ] Abstract: [This presentation presents use cases and requirements for the energy harvesting market] Notice:This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P Mar 2013 Slide 1 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Energy Harvesting Use Cases March 19 th, 2013 Reghu Rajan, Microsemi Mar 2013 Slide 2 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Mar 2013 Slide 3 Reghu Rajan (Microsemi) Abstract This presentation presents use cases and requirements for the energy harvesting market.

doc.: IEEE q Submission What is Energy Harvesting? Definition: Energy from ambient sources harvested for useful purposes Common sources –Light (Photo Voltaic) –Vibration/movements (Piezo-electric, electromagnetic) –Heat flow (Thermo-electric generators) Benefits –Zero Maintenance (deploy and forget, sealed locations) –Extremely long operating life –Long-run cost saving Mar 2013 Slide 4 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Types of EH Systems Energy harvester assisted devices –Requires Battery –EH extends battery life –Long-run average power consumption greater than EH power –Finite life (battery) Energy harvester with storage (WSN) –Harvested energy is used to charge battery/storage device –Long-run average power consumption equal to or less than EH power –Duty-cycled systems that require more power than EH power –Life of battery is the life of node Energy harvester without long-term storage –Does not require battery –Device works only when energy is available –Extremely long life –Ex: EH based switches Mar 2013 Slide 5 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Typical EH Topology Mar 2013 Slide 6 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Requirements for EH based systems Energy harvester efficiency and energy availability –V-I characteristics –Source Impedance –Average power availability –Low aging effects (Mechanical and chemical factors) High-efficiency power management –Capture every micro-joule possible from the EH transducer –Adapt to various I-V characteristics –Extremely low leakage –High-efficiency buck-boost converters –Handle battery chemistries with protection –High efficiency regulators to run application Mar 2013 Slide 7 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Requirements for EH based systems, cont. Low-power sensor and front-end –Low voltage/low noise analog sensor front-end ULP Radio and efficient wireless protocol –Low peak current and low voltage (radio & processor) –ULP processor (leakage, standby/sleep currents, RTC) –Efficient protocol Mar 2013 Slide 8 Reghu Rajan (Microsemi)

doc.: IEEE q Submission EH Transducers (PV) Photovoltaic cells –Most common energy source –Power ranges from micro-watts to watts –Low power management requirements (Peak-power tracking) Mar 2013 Slide 9 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Photo Voltaic Panel Use Cases  PV based smart card  Solar-based wireless environment monitoring  Indoor/outdoor PV based wireless sensors for security and building automation PV Smart Card Example: System peak current requirement <5 mA (radio + CPU) System average current 15 uA (1 min duty cycling) Sub-GHz radio Efficient protocol (Point-to-point or mesh) Onboard thin-film battery Long battery life (>10 years) TX Power less than 0dBm typically Mar 2013 Slide 10 Reghu Rajan (Microsemi)

doc.: IEEE q Submission EH Transducers (Piezo) Piezo-electric Transducers –Impulse energies –Transient V-I characteristics –Demanding power management Uses –Remote control –Lighting control –Vibration sensing (Sense machine wear & tear) –TPS (Tire Pressure Sensor) Mar 2013 Slide 11 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Piezo Transducer based Use-case  Harvested energy per click: 10 to 30uJ  10uJ -> 5mA for 1ms at 2V  Transducer life cycle: >10 Million  Typical payload ~ 11 bytes Mar 2013 Slide 12 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Piezo Transducer based Use-case  Piezo based floor tiles  Building automation (lighting, climate)  Foot traffic logging and occupancy sensing  Security  Industrial monitoring  Vibration monitoring (Wear and tear)  Fitness industry Mar 2013 Slide 13 Reghu Rajan (Microsemi)

doc.: IEEE q Submission EH Transducers (TEG) Thermo-electric generators (TEG) –Steady source –Low power management demand –Low aging –Solid state (no moving parts) –Withstands extreme environments (Military) Mar 2013 Slide 14 Reghu Rajan (Microsemi)

doc.: IEEE q Submission EH Transducers (TEG) Thermo-electric generators (TEG) I-V Curves Example: Industrial transducer Mar 2013 Slide 15 Reghu Rajan (Microsemi)

doc.: IEEE q Submission TEG Transducer based Use-case  Industrial and plant monitoring  Thermal runaway sensing  Heat flow monitoring  Security  Medical/fitness monitoring based on body heat  30uW to 200uW 2V for 3ms at 1 sec duty cycling)  Radio and system peak current is critical (<5mA)  Dynamic duty cycling based on harvested power Mar 2013 Slide 16 Reghu Rajan (Microsemi)

doc.: IEEE q Submission Key Radio requirements  Low voltage operation (~1.2V)  Low peak current (<5mA for complete system)  Low leakage and deep sleep mode (<1uA)  High data rate for duty-cycling, but tradeoff with peak current (~400 kbps)  Lean protocol with low overhead (PPDU < 30 Octets) Mar 2013 Slide 17 Reghu Rajan (Microsemi)