Renesas Electronics America Inc. © 2012 Renesas Electronics America Inc. All rights reserved. Class ID: Energy Harvesting Designs with RL78 Todd Baker, Regional Technical Director Future Advanced Engineering Group CL20I

© 2012 Renesas Electronics America Inc. All rights reserved.2 Regional Technical Director Based in Austin, TX Manages application engineering team south central U.S., Mexico, and South America Renesas technical champion for Future Presenter: Todd Baker Previous experience 5 Years as Field Applications Engineer 5 Years as Design Engineer – Embedded control, vehicle information management, outdoor solar lighting 2 Years as Factory Engineer working on fiberglass doff robotics Education B.S. Electronics Engineering, Texas A&M University M.S. Engineering Management, University of Texas

© 2012 Renesas Electronics America Inc. All rights reserved.3 Renesas Technology & Solution Portfolio

© 2012 Renesas Electronics America Inc. All rights reserved.4 FES Energy Harvesting Platform

© 2012 Renesas Electronics America Inc. All rights reserved.5 Introduction What is energy harvesting? Future energy harvesting platform overview Maximum power point tracking in solar applications Lab Agenda

© 2012 Renesas Electronics America Inc. All rights reserved.6 Why now? Green is IN… companies are looking for new ways to appeal to consumers and businesses. Companies worldwide are investing in R&D dollars to develop new energy harvesting products and support ICs. The technology is final at the tipping point to justify the increase implementation costs vs. the technology benefit. What is Energy Harvesting? Energy harvesting... is the process by which energy is derived from external sources (e.g., solar power, thermal energy, wind energy, salinity gradients, and kinetic energy), captured, and stored for small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks. (Source: Wikipedia)

© 2012 Renesas Electronics America Inc. All rights reserved.7 Future’s Energy Harvesting platform is designed to… Train customers on how to design a energy harvesting system Showcase new low power technologies Allow flexible development overtime to showcase market trends What will we provide design engineers? Energy Harvesting Platform for internal testing for a period of time Complete design files & design assistance Access to new energy harvesting technologies Performance estimates and BOM costs of energy harvesting Development of customer specific modules / circuits for qualified opportunities Future Electronics’ Energy Harvesting Platform

© 2012 Renesas Electronics America Inc. All rights reserved.8 Boards developed and designed by Future Electronics System Design Center Available for loan and demonstration from your local Future Electronics Branch Future Partner Number: TLP-EHP1 Resale Price: $500 Kit updates will occur every 6 months Kits are available for purchase w/o case Program Overview

© 2012 Renesas Electronics America Inc. All rights reserved.9 DC/DC Power Conversion Battery Fuel Cell Super Cap OR… ENERGY STORAGE DC/DC Power Conversion RF Module Sensor Node Light Engine OR… Application PV solar Thermal RF Vibration ENERGY SOURCE Energy Harvesting Platform

© 2012 Renesas Electronics America Inc. All rights reserved.10 Energy harvesting applications need: Low Power consumption in application circuitry Low Power consumption in harvesting power conversion circuitry (MPPT, etc) RL78 meets the needs on both sides! Best operating current levels – 66uA/MHz Incredibly low power states – 230nA w/ RAM retained Wide operating range – 1.6V to 5.5V Snooze mode peripheral operation – Can result in 30% power savings (ADC) Highly integrated – Few external parts needed! Why For Energy Harvesting?

© 2012 Renesas Electronics America Inc. All rights reserved.11 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB Micro Adaptor Module M M M M R RR R Energy Harvesting Platform

© 2012 Renesas Electronics America Inc. All rights reserved.12 Application DC/DC Module Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Micro Adaptor Module socket Mother Board Mini USB Micro Adaptor Module M M M M R RR R Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Mother Board and Processor Module

© 2012 Renesas Electronics America Inc. All rights reserved.13 Read IDs of the attached modules Ensure the platform is performing within the voltage and current limits of the system Read and process the current and voltage measurements for each module Control the relays on the mother board Store the measurement data to a SD Card and/or transmit the data to the PC interface System can accept up to 30V and 2A Mother Board and Processor Module

© 2012 Renesas Electronics America Inc. All rights reserved.14 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Micro Adaptor Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB M M MM R RR R MCU Module

© 2012 Renesas Electronics America Inc. All rights reserved GPIO lines for controlling system. I2C Bus SPI Bus UART Port 3.3v Power provided from motherboard. Signals to / from the mother board Micro Adaptor Module

© 2012 Renesas Electronics America Inc. All rights reserved.16 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB M M MM R RR R Micro Adaptor Module Energy Harvesting Module

© 2012 Renesas Electronics America Inc. All rights reserved.17 Sharp LR0GC02 Solar Panel Open circuit voltage (Voc): 5.7V Typical, 5.2V Min Short circuit current (Isc): 75mA Typical, 62mA Min Maximum power voltage (Vpm): 4.5V Typical, 3.8V Min Maximum power current (Ipm): 65mA Typical, 48mA Min Maximum power (P ｍ ): 300mW Typical, 240mW Min Energy Harvesting Module

© 2012 Renesas Electronics America Inc. All rights reserved.18 Energy Harvesting Module I2C data Output voltage and current to the DC/DC block On board EEPROM stores I.D. number, calibration data, etc. Memory select from micro Basic function: Harvest ambient solar energy Vo (Max) (V)Io (max) (mA)Impp (mA)Vmpp (V)Pmpp (mW) Temp sense for MPPT SCR001 Sharp LR0GC02 Energy Harvesting Module

© 2012 Renesas Electronics America Inc. All rights reserved.19 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB M M MM R RR R Micro Adaptor Module Harvesting DC/DC Module

© 2012 Renesas Electronics America Inc. All rights reserved.20 Ideal World Solar Harvesting

© 2012 Renesas Electronics America Inc. All rights reserved.21 Temperature Higher temperature increases series resistance of panel Shading on panel Non irradiated cells have high impedance and lower current output Storage System Voltage Level Solar panel output voltage will match level of the battery This generally will not allow maximum power output of panel Causes of Solar Harvesting Inefficiency

© 2012 Renesas Electronics America Inc. All rights reserved.22 Causes of Solar Harvesting Inefficiency

© 2012 Renesas Electronics America Inc. All rights reserved.23 Maximum Power Point Tracking Boost Converter Circuit V SP I SP PWM Output

© 2012 Renesas Electronics America Inc. All rights reserved.24 Perturb and Observe Methodology Utilized Maximum Power Point Tracking Algorithm Calculate Present Power P Present - P Past Did Power Increase? Was Duty Cycle Raised? No Was Duty Cycle Raised? Yes Raise DCDrop DC YesNo Raise DCDrop DC YesNo

© 2012 Renesas Electronics America Inc. All rights reserved.25 Vastly improved utilization of solar panel energy Faster recharge rates Limited only by losses in MPPT circuitry Reduce the number of panels required in system Can be modified to easily implement added safety features Monitor for overcurrent conditions and shut down Should not be utilized in systems with ultra low power requirements Losses from MPPT circuit power eliminate any efficiency advantages Benefits of MPPT on Solar System

© 2012 Renesas Electronics America Inc. All rights reserved.26 Harvesting DC/DC Module Power input from the energy harvesting source. Power output to the energy storage solution. I2C data On board EEPROM stores I.D. number, calibration data, etc. Basic function: Provide stable voltage and current to the energy storage block Board Part Number: EHAR-002 Quotient CurrentVi (Min)Vi (Max) Ii (Max)Vo (Max)Io (Max) 2.5mA3.4V5.7V40mA5V90mA Memory Select from Micro Over voltage info from storage Harvesting DC/DC Module

© 2012 Renesas Electronics America Inc. All rights reserved.27 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB M M MM R RR R Micro Adaptor Module Energy Storage Module

© 2012 Renesas Electronics America Inc. All rights reserved.28 Illinois Capacitor: 105DCC5R5ZMH Very fast charge/discharge cycling WVDC: 5.5 Volts DC SVDC: 6 Volts DC Operating temperature: -25°C to +70°C Maximum stored energy: Watt hours Maximum Current: 2.75 Amps (1 second discharge to 1/2 the rated voltage) Operating Current: Amps (5 sec discharge to 1/2 rated voltage) Load Life: 1000 hours at 70°C with 100% of rated voltage applied RoHS compliant and IEC compliant Energy Storage Module

© 2012 Renesas Electronics America Inc. All rights reserved.29 Energy Storage Module I2C data On board EEPROM stores I.D. number, calibration data, etc. Output of energy harvesting DC/DC module Input to application DC/DC module Quotient CurrentVi (Max)Vo (Max)Capacitance 15uA4.5V4.68V2F Basic Function: Store the harvested energy STR001: Two 2F Super Caps 105DCC5R5ZMH Memory select from micro Over voltage info from storage Energy Storage Module

© 2012 Renesas Electronics America Inc. All rights reserved.30 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB M M MM R RR R Micro Adaptor Module Application DC/DC Module

© 2012 Renesas Electronics America Inc. All rights reserved.31 Harvesting DC/DC Module Power input FROM the energy storage source Power output to the application module I2C data On board EEPROM stores I.D. number, calibration data, etc. Basic Function: Provide stable voltage and current to the application module Board Part Number: APDC001 Quotient CurrentVi (Min)Vi (Max)Vo (Max)Io (Max) 35uA0.85V5V3.3V200mA Memory Select from Micro Application DC/DC Module

© 2012 Renesas Electronics America Inc. All rights reserved.32 Energy Storage Module Application Module Energy Harvesting Module Harvesting DC/DC Module Application DC/DC Module Indicates Energy Flow M = Measurement Circuit Block R = Relay Block Micro Adaptor Module socket Mother Board Mini USB M M MM R RR R Micro Adaptor Module Application Module

© 2012 Renesas Electronics America Inc. All rights reserved.33 I2C data On board EEPROM stores I.D. number, calibration data, etc. Basic Function: Provide stable voltage and current for the app module. The resistive load allows user to test different power conditions and external PWR pins are provided. Board Part Number: APP002 Vi (Max)Ii (Max) 3.3V64mA Application Module Power output from the app DC/DC module Memory select from micro Application Module

© 2012 Renesas Electronics America Inc. All rights reserved.34 Smart Pixel Display Comm for Power Mode Control Joystick Remote Access Panel or Remote Control RL78 powered from super capacitor array on Energy Storage Module Keypad and joystick used for user interface with appropriate output to smart pixel display User can utilize different power modes of RL78 to monitor behavior on energy harvesting platform software Interface Application Module

© 2012 Renesas Electronics America Inc. All rights reserved.35 Begin Lab w/ Future Electronics Energy Harvesting Platform

© 2012 Renesas Electronics America Inc. All rights reserved.36 Questions? Questions?

© 2012 Renesas Electronics America Inc. All rights reserved.37 Please utilize the ‘Guidebook’ application to leave feedback or Ask me for the paper feedback form for you to use… Please Provide Your Feedback…

Renesas Electronics America Inc. © 2012 Renesas Electronics America Inc. All rights reserved.

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