ADVANCED POWER SOLUTIONS FOR WEARABLE TECHNOLOGY AND INTERNET OF EVERYTHING SENSORS WEBINAR ©2014 Cymbet Corporation All Rights Reserved Webinar Agenda 1. Wearable Technology and Internet of Everything market dynamics 2. Examine WT and IoE system components and powering options 3. Techniques for harvesting ambient energy to recharge devices 4. New technologies and the cost trade-offs for advanced power solutions 5. Design tips for building ultra-low power systems with long battery life 6. Examples of real-world Energy Harvesting-powered WT and IoE devices www.cymbet.com Ph: +1 763-633-1780 2 The Key Trends Driving Innovation for Internet of Everything and Wearable Tech Ultra Low Power Processors & Electronics Smart Devices and Sensors Everywhere Wireless is pervasive Integration with other components Miniaturization Eco-Friendly and Renewable Energy Convergence of Trends into Products • • • • • New innovative products are smarter, smaller and wireless Smart devices that must communicate status/control There will be billions of new networked smart devices Health, Industrial, Buildings, Appliances, Transportation New Efficient and Cost-Effective Powering solutions needed www.cymbet.com Ph: +1 763-633-1780 3 25 Years of Device Evolution to IoE Fixed Computing to Internet of Everything Source:Cisco www.cymbet.com Ph: +1 763-633-1780 4 HP, IBM, Google, Cisco, et al… Giving the Planet a Voice with Sensors HP CeNSE Project IBM Smarter Planet “Trillions of digital devices connected to the Internet, are producing a vast ocean of data…” “The Internet of Everything builds on the Internet of Things by adding network intelligence and security that allows convergence, orchestration and visibility across disparate systems. But…. Who’s going to change 1 Trillion Batteries????! www.cymbet.com Ph: +1 763-633-1780 5 Use Energy Harvesting vs. Primary Batteries Energy can be harvested from almost any environment: • Light, vibration, flow, motion, pressure, magnetic fields, RF, etc. Energy Harvesting applications found in every industry segment EH-powered systems need reliable energy generation, storage and delivery: • Must have energy storage as EH Transducer energy source is not always available: (Solar @night, motor vibration at rest, air-flow, etc.) • Longer operating times – high-efficiency minimizes charge loss • Self-Powered allows remote locations & lower installation costs • High cycle life enables extended operation – fewer service calls Ideal solution is a highly-efficient, eco-friendly, power generation system that can be cycled continuously for the life of the product www.cymbet.com Ph: +1 763-633-1780 6 EH Power Range for IoE and Wearables www.cymbet.com Ph: +1 763-633-1780 7 Energy Harvesting Powered Wireless Sensor Diagram “Energy Aware” Systems measure and report EH input power and Battery state of charge to optimize operation www.cymbet.com Ph: +1 763-633-1780 8 Key Design Issue for EH-Powered Systems 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Current Current High efficiency designs Minimize losses (on-resistance, coil resistance, ESR, leakage, …) Minimize average standby/sleep power Reduce wireless TX/RX power and/or lengthen radio pulse duty cycle Maximize harvested power through the power chain 0 20 40 60 80 100 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 20 40 60 80 100 Time Time www.cymbet.com Ph: +1 763-633-1780 9 Energy Harvesting Transducers What Ambient Energy is Available? Energy Source Challenge Typical Impedance Typical Voltage Typical Power Output Light Conform to small surface area; wide input voltage range Varies with light input Low kΩ to 10s of kΩ DC: 0.5V to 5V [Depends on number of cells in array] 10µW-15mW (Outdoors: 0.15mW15mW) (Indoors: <500µW) $0.50 to $10.00 Vibrational Variability of vibrational frequency Constant impedance 10s of kΩ to 100kΩ AC: 10s of volts 1µW-20mW $2.50 to $50.00 Thermal Small thermal gradients; efficient heat sinking Constant impedance 1Ω to 100s of Ω DC: 10s of mV to 10V 0.5mW-10mW (20°C gradient) $1.00 to $30.00 RF & Inductive Coupling & rectification Constant impedance Low kΩs AC: Varies with distance and power 0.5V to 5V Wide range $0.50 to $25.00 Cost Designs must deal with different: Impedance, Voltages, Output power, etc. www.cymbet.com Ph: +1 763-633-1780 10 Using Maximum Peak Power Tracking (MPPT) Match the Impedance of the Energy Harvesting Transducer Source to the Impedance of the Load using Maximum Power Point Tracking circuitry to provide the highest efficiency harvesting. www.cymbet.com Ph: +1 763-633-1780 11 EH Power Conversion Techniques MPPT algorithms • Incremental conductance (ΔP/ΔV) • P&O • Fractional OCV Hill climbing algorithms Fractional OCV (Open Circuit Voltage) • MPP voltage has a fixed ratio to open circuit voltage (0.7 – 0.8) • But: Ratio not constant and different for every generator Perturb & Observe • Generic algorithm • Oscillates around MPP www.cymbet.com Ph: +1 763-633-1780 12 Variable Impedance EH Transducer - Solar www.cymbet.com Ph: +1 763-633-1780 13 Constant Impedance – Thermal, Piezo, Electromagnetic www.cymbet.com Ph: +1 763-633-1780 14 Solar Power Management Example • Series / parallel combinations optimize panel voltages (1 to 4 volt range) • Maximum power point tracking / control optimizes energy transfer • Example: Cymbet CBC915 Energy Processor chip www.cymbet.com Ph: +1 763-633-1780 15 MPPT with Thermoelectric Generator TEG has various Power outputs at different Temperature gradients and Peak Power Point occurs at different places. An example hill-climbing MPPT algorithm is shown to arrive at the Peak Power Point www.cymbet.com Ph: +1 763-633-1780 16 EH vs. Primary Battery Costs Comparisons • Small device designs that do not have a charging source – either AC/DC, Energy Harvesting or Wireless Power – use a primary battery • Primary batteries have reached commodity status with billions/year shipped • How to compare cost of Energy Harvesting to Primary Batteries? • Model the Energy Harvester as a variable capacity battery and divide the cost of the EH components by the amount of energy created over the life of the EH-powered system. www.cymbet.com Ph: +1 763-633-1780 17 Calculate the $/mAh for Batteries • Example using 3Volt batteries 1K Quantity from Distributors: • • • • CR2032 coin + holder: $.36/225mAh x 1 cycle = $0.0016/mAh Tadiran coin: $4.82/1000mAh x 1 cycle = $0.0048/mAh Alkaline 2 AAA + holder: $1.71/1000mAh x 1 cycle = $0.0017/mAh Cymbet EnerChip: $2.70/50uAh x 10,000 cycles = $0.0054/mAh • To charge rechargeable batteries, need to add the Cost for EH power system • Supercapacitors can be used, but electrical characteristics are a concern www.cymbet.com Ph: +1 763-633-1780 18 Calculating the $/mAh of the Energy Harvester • • • • • • Think of the Energy Harvester as a variable capacity battery The output energy will depend on the ambient energy conditions Energy Harvester designs will have a min/max energy output range Calculate the EH cost based on the energy output average Cost is Transducer + interface components+ storage + conversion electronics (IC) Example: Simple Solar Energy Harvester at 400Lux with 24/7 operation • Sanyo AM1815 4.9V solar cell $4.39 (1K pcs) output is 294uW • Assume simple conversion electronic components for $1.25 • EnerChip Batteries – 200uAh total capacity $4.10 • 294uW/3.3V = 89microAmps output from Solar Harvester • Total capacity over 10 year 24/7 life = 7796 mAh • $/mAh for Solar EH = $0.0013/mAh. Lower than AAA and Coin cell costs Energy Harvesters can be designed as cost effectively as Primary Batteries www.cymbet.com Ph: +1 763-633-1780 19 Assigning $ Value to EH-Power Solution over Batteries 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Primary Battery Change-out – device access and cost of replacement What is the product power lifetime requirements – 200mAh, 1Ah, 10Ah? Life of product duration expectations – 3, 5, 10, 20 years? Battery Footprint and overall product size Battery Height and overall product size $cost/uAh/mm3 - how much energy for $ in how small a space? Assembly Issues and Costs Product Physical design – No doors or customer access Electrical Characteristics - flat voltage, fast recharge, low discharge Aging Characteristics – chemical leakage, seals drying out Transportation Restrictions – UN and Country Air Safety shipping laws Safety and End-of-Life Disposal - what are the procedures and costs www.cymbet.com Ph: +1 763-633-1780 20 EH Power System Cost vs. Benefit $ Cost vs. $ Benefit vs. Requirements www.cymbet.com Ph: +1 763-633-1780 21 “Watt a waste…..” www.cymbet.com Ph: +1 763-633-1780 22 IoE Needs a New Type of Battery www.cymbet.com Ph: +1 763-633-1780 23 Cymbet Rechargeable Solid State Batteries Solid State Cathode EnerChip Co-packaged EnerChips on Silicon Wafers Solid State Battery & PMU Anode Current Collector Cathode • Solid State Electrolyte Electrolyte Charging Protective Coating Current Collector Substrate Discharging Manufactured with standard silicon CMOS-type processes. Small Chip-scale footprint - bare die or packaged parts - 150 microns thick Thousands of Recharge cycles – “life of product” Fast recharge – 80% in 10 minutes Ultra-low self-discharge + flat discharge profile - Uniquely suited to Energy Harvesting Reflow tolerant for low cost automated assembly SMT - >360⁰C Completely Eco-Friendly; No heavy metals, liquids, binders, etc As a silicon-based device, can be co-packaged or embedded with MCUs, RTCs, etc. www.cymbet.com Ph: +1 763-633-1780 24 Solid State Batteries Used in Several Applications www.cymbet.com Ph: +1 763-633-1780 25 Comparing Energy Storage Options SSB = Best of Both Worlds High Drive Current High Energy Density 50 X SuperCap Lowest Leakage 4,000 X < SuperCap Rechargeable / Long Life Superior Lifetime Energy – never replace a battery www.cymbet.com Ph: +1 763-633-1780 26 Solid State Batteries Provide Key EH Battery Requirements Need: • 1000’s charge cycles • Flat Output voltage • Fast Charge • Low Self Discharge www.cymbet.com Ph: +1 763-633-1780 27 Solid State Batteries Shrink Sensors Reducing the IoE Sensor size 144,000x www.cymbet.com Ph: +1 763-633-1780 28 4 Key Techniques for Successful EH Designs 1. Determine energy available from your environment • Type of Energy Source(s), Amount of Energy, Duty Cycle 2. Harvest energy as efficiently and cost effectively as possible • Use MPPT or optimized circuits 3. Calculate application power requirements in all operation modes and minimize design to fit available input EH power • System Start-up Power, Sleep, Radio TX/RX, Sensing, Leakage, etc. 4. Size storage for times when ambient energy is not available • Almost all systems need rechargeable storage device www.cymbet.com Ph: +1 763-633-1780 29 Industry is Providing Ultra-Low Power Solutions for IoE Low Power Microprocessors with nanoAmp sleep currents • TI, Renesas, Microchip, NXP, Silicon Labs, etc. Low Power Radio Transceivers and Energy Efficient Protocols: • 802.15.4 Zigbee, 6LoWPAN using IP, Bluetooth Smart, ANT +, EnOcean Micro-power Sensors with low sleep currents • Sensiron, NXP, TI, others…. Lower quiescent current peripheral circuits – PMICs, timers, A/D, etc. www.cymbet.com Ph: +1 763-633-1780 30 Techniques for running IoT Sensors on 1uW Avg. Power Off-the-shelf MCUs are capable of 1uW computing • Acceptable Performance at 1-2KIPS (not 1-2MIPS!) • Utilize Sensor samples at 1-10 SPS • ULP standby clock • Instant-on and very accurate high-speed clock • I/O, interrupt capability, and all RAM retained Traps • • • • • • Firmware – no loops, all interrupts Temperature increases leakage significantly Floating inputs Multiple voltage domain satiation Watch for un-deterministic clocking Where to get a 2V supply in a real application? www.cymbet.com Ph: +1 763-633-1780 31 Power Switching Technique for WT and IoE Optimization There may be situations where the components used in the design have high power operation. In this case, a Power Switching technique called an “Enerrupt” can be implemented. The power in the WT or IoE system is switched on/off by a timer device An ideal device for this implementation is the Cymbet EnerChip RTC CBC34803 (I2C-bus) or CBC34813 (SPI). In the lowest power timer mode, the EnerChip RTC uses only 14nA of current. www.cymbet.com Ph: +1 763-633-1780 32 “Enerrupt” System Power Using an EnerChip RTC Fig 1: Switched VSS (Ground) Configuration CBC34803 VCC I2C VSS nIRQ2 VCC MicroController VSS VCC Sensor /Switch VSS Fig 2: Switched VCC Configuration CBC34803 VCC I2C VSS nIRQ2 VCC MicroController VSS www.cymbet.com Ph: +1 763-633-1780 VCC Sensor /Switch VSS 33 Example Power Savings from using Enerrupt Circuit Application Note AN-1059 Power savings calculations have several variables to balance – Active run times, sleep periods, active time/sleep time and number of instructions. Power Savings Ratio shows battery extension of up to 11 times Power Savings with Periodic Interrupt Original Sleep current in uA uA/Mhz Mhz 0.6 200 0.6 200 0.6 200 0.6 200 0.6 200 0.6 200 0.6 200 0.6 200 1.6 200 1 1 1 1 1 1 1 1 1 Power Active Active Current Runtime in Sleep Period in When Running Number of Savings Active Time / Instructions Ratio ms Sleep Time ms (ua) 0.1 16 200.000 0.0063 100 0.47 0.1 33 200.000 0.0030 100 0.97 0.05 33 200.000 0.0015 50 1.89 0.1 100 200.000 0.0010 100 2.80 0.05 100 200.000 0.0005 50 5.26 0.1 250 200.000 0.0004 100 6.38 0.05 250 200.000 0.0002 50 11.11 0.2 250 200.000 0.0008 200 3.45 0.3 250 200.000 0.0012 300 6.30 www.cymbet.com Ph: +1 763-633-1780 34 Bluetooth Smart Wearables Will Scale Faster due to Simple Interoperability www.cymbet.com Ph: +1 763-633-1780 35 Bluetooth Smart EH-Powered Beacon Courtesy: Dialog Semiconductor www.cymbet.com Ph: +1 763-633-1780 36 BLE Beacon Tear Down Courtesy: Dialog Semiconductor Dialog DA14580 BLE radio, Solar Cell to TI BQ25504 PMIC with Cymbet EnerChip CBC050 rechargeable solid state battery www.cymbet.com Ph: +1 763-633-1780 37 EH-Powered Wearable Intra-Ocular Pressure Sensor All the EH-powered sensor components are here: Sensor, Energy Storage, MCU with A/D, Solar Cell and Radio with Antenna www.cymbet.com Ph: +1 763-633-1780 38 Example of Wireless EH-Powered Smart Contact Lens Concept Ultra Low Power Management IC Designs Integrated with MCU and Radio Cymbet EnerChip Non-Cytotoxic Rechargeable Solid State Battery Wireless Communication to Smartphone and Wireless Charging www.cymbet.com Ph: +1 763-633-1780 39 Summary • Billions of smart devices deployed over the next 10 years need to: • Be powered autonomously and be “off-grid” • Have a power source that lasts the life of the device • Be small, integrated and cost effective • Cost effective Energy Harvesting solutions can power products • Success is based on the EH Ecosystem converging: • EH Transducers • High Efficiency power conversion • Life of Product Energy storage • Ultra low power Microcontrollers and Sensors • Low power wireless radios and protocols • Optimized system architecture, hardware and firmware www.cymbet.com Ph: +1 763-633-1780 40 Q&A, Resources and Evaluation Kits: Free Executive Briefing that supports this presentation: “Powering Wearable Technology and Internet of Everything Devices” can be found here: http://www.cymbet.com/design-center/white-papers.php Register to win a free Cymbet Energy Harvesting evaluation Kit here: http://www.cymbet.com/win-a-free-enerchip-evaluation-kit.php Cymbet EnerChip solid state battery datasheets, application notes, Case Studies and Reference Design documents are here: http://www.cymbet.com/products/datasheets-downloads.php Steve Grady – [email protected] www.cymbet.com Ph: +1 763-633-1780 41