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

Energy Harvesting Solutions

© 2012 Renesas Electronics America Inc. All rights reserved.2

Cymbet Smart Rechargeable Solid State Batteries Energy Harvesting Power for Wireless Platforms

Previous Experience ASIC, GPS Program Management Semiconductor marketing and sales

Education BS St. Louis University

Bill Gross, Business Development Director


Renesas Technology & Solution Portfolio


Microcontroller and Microprocessor Line-up

Wide Format LCDs Industrial & Automotive, 130nm 350µA/MHz, 1µA standby

44 DMIPS, True Low Power

Embedded Security, ASSP

165 DMIPS, FPU, DSC

1200 DMIPS, Performance1200 DMIPS, Superscalar

500 DMIPS, Low Power

165 DMIPS, FPU, DSC

25 DMIPS, Low Power

10 DMIPS, Capacitive Touch

Industrial & Automotive, 150nm 190µA/MHz, 0.3µA standby

Industrial, 90nm 200µA/MHz, 1.6µA deep standby

Automotive & Industrial, 90nm 600µA/MHz, 1.5µA standby

Automotive & Industrial, 65nm 600µA/MHz, 1.5µA standby Automotive, 40nm

500µA/MHz, 35µA deep standby

Industrial, 40nm 200µA/MHz, 0.3µA deep standby

Industrial, 90nm 1mA/MHz, 100µA standby

Industrial & Automotive, 130nm 144µA/MHz, 0.2µA standby

2010 2012

32

-bit

8/16

-bit

8/16-Bit True Low PowerHigh Efficiency & Integration


Challenge: “In the smart society sensors and displays are no longer tethered to power lines or network cables. Sensors will be on our bodies, our pets, in remote fields and they will have to run for many years on small batteries or utilizing energy harvesting techniques.”

Solution:“This class will teach attendees how to implement energy harvesting in an application. We will discuss examples of energy harvesting sources, storage methods, explain concerns for energy harvesting applications, and demonstrate how to use an RL78 MCU to solve these problems. ”

‘Enabling The Smart Society’


Why Energy Harvesting?

Energy Harvesting Target Applications

Energy Harvesting Sources

Understanding Energy Harvesting Anatomy

Battery Technology to Address Energy Harvesting

Example Energy Harvesting Application

Questions

Agenda


1821, Thomas Seebeck

Energy Harvesting an Ancient Science

1883, Charles Fritz 1880, Jacques & Pierre Curie

Thermoelectric Effect

Solar Cell Piezoelectricity


Energy Harvesting: Why Now?


Technological advancements have made Energy Harvesting deployable

Large number of ultra low power components (wireless MCUs) introduced that make Energy Harvesting more commercially viable

#1: We have Reached a Tipping Point


Big leaps in rechargeable battery technology Batteries today a lot smaller Target applications where batteries are Inconvenient

to replace

#2: Energy Storage Technology Advancements


Conventional energy sources are not inexhaustible They produce large green house gases Are getting progressively more expensive

#3: Let’s be Green


Energy Harvesting: Starting To Get Pervasive

Lowly calories converted to precious watts

Microgym - Portland, oregonReduced Energy Bills by 60%!

Cell phone - samsung11% Efficiency

New energy tech.

250 million registered vehicles which drive more than 6 billion miles on America’s roadways every day.


Where does Energy Harvesting Make Sense?

Energy Harvesting solutions address many markets Low Data Rate Low Duty Cycle Ultra Low Power

Health & FitnessMedical

Building/Home Automation

StructuralMonitoring


Where Does Energy Harvesting Make Sense?

One or more characteristics have to be met in order to implement energy harvesting

Energy source readily available

Heavy usage of cords

Can’t afford downtime

Large number of devices

Environmentally friendly


Energy Source Vs. Harvested PowerEnergy Source Harvested PowerTemperature (Pyroelectric) 10 μW/cm3

Ambient Radio Frequency 1 μW/cm2

Ambient Light 100 mW/cm2 (Direct Sun)100 μW/cm2 (Office Light)

Thermoelectric 60 μW/cm2

Vibration (micro generator) 4 μW/cm3 (Human Motion Hz)800 μW/cm3 (machines-KHz)

Vibrations (Piezoelectric) 200 μW/cm3

Airflow 1 μW/cm2

Shoe Inserts 330 μW/cm2

Hand Generators 30 W/KgHeel Strike 7 W/cm2

Source: Journal of Technology Studies; Potential Ambient Energy-Harvesting Sources and Techniques by Faruk Yildiz (2005)


Energy Harvesting Block Diagram

Solar Thermal RFVibration

sensor unit

Harvester(generator) Power

Management

Power

MCU RF

SensorAFE

Power Supply Unit

rechargeablebattery

Control unit


Changes in System Requirement

MCU RF

Conventionalbattery

Sensor

Common power line supplied by conventional battery

Typical Systemwith Conventional Battery

RechargeableBattery

RF

MCU

Sensor

alwaysrunning

↓

Power Management Unit Always ON

Energyharvester

Conventionalbattery

Ex. Intelligent power management +RTC+Serial communication (IIC), Memory

Powermanagement

The Emerging System with Energy Harvester

Sensor

MCU RFConventionalbattery

Electric power supplied only when the peripheral devices have to work

Conscious of Power Consumption


RL78 : True Low Power MCU

Communication

8 x I2CMaster

2 x I2CMulti-Master

8 x CSI/SPI7-, 8-bit

4 x UART7-, 8-, 9-bit

1 x LIN1ch

Analog

ADC10-bit,12-bit, 26ch

Internal Vref.

Memory

Program Flashup to 512KB

SRAMup to 32KB

Data Flashup to 8KB

System

DMA4ch

Interrupt Controller4 Levels, 20 pins

Clock GenerationInternal, External

Power Management

HALTRTC, DMA Enabled

SNOOZESerial, ADC Enabled

STOPSRAM On

Timers

2 x Timer Array16-bit, 16ch

Interval Timer12-bit, 1ch

WDT17-bit , 1ch

RTCCalendar

Temp. Sensor

Safety

RAMParity Check

POR, LVD

MUL/DIV/MAC

DebugSingle-Wire

ADCSelf-diagnostic

ClockMonitoring

MemoryCRC

RL78 CPU Core 16-bit CISC, 44 DMIPS at 32MHz

Power Management Operating: as low as 66uA/MHz (NoOp) Active: 144uA/MHz Halt: 0.57µA (RTC + LVD) Stop: 220nA (RAM retained) Snooze: 580uA (UART), 780uA (ADC)

System +/- 1% Internal Oscillator (32MHz, 24MHz) 16x16 Multiplier, 32/32 Divider, Multiply-

Accumulate 1.6V – 5.5V Operating Voltage Range

Analog 1.6V (Vcc) operation 26 channels, 10-bit,12-bit 2.1µs conversion

time Internal Voltage Reference (1.44V)

Communication SPI, UART, I2C, LIN

Package 25LGA (3x3)


Design Considerations for EH-Powered Systems Determine energy available from your environment

Indoor solar is in tens to hundreds of microwatts Thermoelectric in tens to hundreds of microwatts based on

delta Temperature Harvest energy as efficiently as possible

Design for Maximum Peak Power Point Avoid components with excessive leakage or quiescent current

Calculate application power requirements and minimize to fit available input EH power Use sleep modes of components when possible Write Energy- Aware code -> no polling loops, check Vcc

before running Size storage for times when energy is not available

Bigger battery is not always better: don’t fill the pool with a paper cup!


Energy Harvesting Power Conversion, Storage and Mgmt

Power TransducerPhotovoltaic

ThermoelectricPiezoelectric

InductiveRF

ΔTemp

MotionVibration

EM Field

Energy Processing & StoragePower Conversion & ConditioningPower ManagementEnergy Storage

EnerChip™ EPCBC-915 or

CBC3150 CCEH

OptionalMCU + Radio

Light

• Need high efficiency energy conversion and power management• Need rechargeable energy storage devices – batteries or supercapacitors


EnerChip™ CC Family – Energy Conversion andEnergy Storage Designers need a reliable energy storage device with:

Thousands of recharge cycles, Low self Discharge, Flat Vout Reflow Tolerant, Surface Mount Technology & Assembly Process 3.3V compatibility, Power-fail detect & Automatic back-up Drop-in solution, Small footprint & Minimal external component count

EnerChip CC is EH Converter and Battery in a Chip!

EnerChip CC Features:• CBC3150 – 50uAhr, 9 x 9 mm• CBC3112 – 12uAhr, 7 x 7 mm• CBC3105 – 5uAhr, 4 x 5 mm

(Available Q3-2011)• < 1mm Thick, DFN SMT• Expand up to 9 CBC050s

Devices - 500uAHr• Integrated CBC050 EnerChip,Threshold control, Power-Fail Detect & Charge Pump

• High-Value solution


Solar Energy Harvesting using Pulse Width Modulation Techniques

VIN

RESETN/EN Fly Cap –Cpump running


Variable Impedance Transducers - SolarMaximum Peak Power Tracking


Constant Impedance Transducers – Thermal, Piezo


Cymbet Energy Processor for Universal Energy Harvesting High efficiency EH transducer input power conversion from

transducers Uses Maximum Peak Power Tracking algorithms Provides energy storage device management Power output regulation with Energy Aware system management

Energy Processor on EVAL-09 EH Kit


Energy Storage Options

Feature Li-Ion Thin Film Supercapacitor

Recharge Cycles 100s 5K – 15K 100-500K

Self Discharge Moderate Negligible High

Charge Time Hours Minutes Several-Minutes

SMT & Reflow Poor-None Good Poor

Physical Size Large Small Medium

Capacity 0.3 – 2500 mAH 12 – 700 uAH 10 – 100 uAH

Environment Impact

High Minimal Minimal


Using Solid State Batteries for Zero Power Wireless Devices

Ultra Low Power

Processors

Smart Devices and

SensorsEverywhere

Wireless is pervasive

Integration withother

components

Miniaturization

Eco-Friendly and

Renewable Energy

HP: 1 trillion

sensors in 5 years

60 mm wireless devices annually

Solar poweredsensors

Complete wireless

sensor with power

800mm Micro machines in a

package

10 year components Pennies to dollars

Low energy for Space used

Bulky Size/Metal “coin” package

Not Eco-Friendly - Toxic Chemicals

Transportation Safety Issues

Requires holders and secondary assembly

TRENDS

CURRENT SOLUTIONS

Coin Cell Batteries Supercapacitors


The Solution:EnerChip™ Smart Solid State Batteries

Core of technology is lithium conducting amorphous glass electrolyte Lithium phosphorous oxynitride (LiPON) Good ionic conductivity; electronic insulator Low self-discharge

EnerChips on Silicon Wafer

• Li ions transported across electrolyte during cycling• Electrons blocked from transport by glass electrolyte

Lithium Cobalt Oxide Cathode and Lithium Free Anode Crystalline structure permits thousands of charge-discharge cycles No pastes, gels, binders, or other additives Excellent charge/discharge rate capability Constant voltage/any current charging mechanism


Wafer

Diced

Bare Die Packaged Part

Packaged

To Surface Mount MachineTo Reflow Solder

Final Assembly

SSB on Board

Surface Mount AssemblySolid State Battery is Reflow Solder Tolerant

Tape & Reel

Surface Mount AssemblySolid State Battery is Reflow Solder Tolerant


Solid State Batteries Have Key Attributes for EH Systems

Capacity with Cycling

0

10

20

30

40

50

60

70

0 100 200 300 400 500 600 700 800 900 1000Discharge Cycle #

Cap

acity

(µA

h) 4.2V

4.15V

4.1V

4.3V

4.0V

High Cycle Life Flat Output Voltage Profile

Charge Current & Charge Capacity vs, Charge Time

0 10 20 30 40 50 60

120

100

80

60

40

20

0

Perc

ent o

f Cha

rge

Time (Minutes)

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

Char

ge C

urre

nt/

Batt

ery

Capa

city

Fast and Simple Charge

Char

ge Lo

ss %

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

Stand Time (Years)1 2 3 4 5

Non-Recoverable

Recoverable

Self-Discharge

Low Self-Discharge


Optimizing EH-Powered Wireless Sensors

Extended Ultra-Low Power standby modeMinimum active duty cycle Interrupt driven performance on-demand

1uA

Active

‘Stand-By’


EH Power and System Performance Analysis

Photovoltaic Cell18 cm2 x 5.36 uW/cm2

@ 200 Lux = 97uW (Low light conditions –Power output scales

linearly with Lux input)

Energy ConversionUnder 100uW is 50%

efficient due to electronics = 50uW

Battery Charging100uAh battery

charges at 4.06V so rate is 12uAh - takes ~8 hours to recharge

with no activity

Ultra Low Power System Standby Power UsageAssume 1uA/hour

Wireless Radio Power100uAh Battery has 1260mJ capacity after System Load

drain and efficiencies ~1000mJ for 392uJ radio

pulses = 2500 radio pulses/charge

Uses 12 uAhr over 12 hours


Examples of Real World Energy Harvesting Systems

Intra Ocular Pressure Sensor uses Solar100’s picoWatts to 100’s nanoWatts power

Forest Fire Detection System Uses pH Differential 100’s milliWatts power

Entry Security Wireless Sensor Uses Solar100’s microWatts to 10s milliWatts power

Data Logger uses RF Wireless Harvesting100’s microWatts to 10’s milliWatts


Energy Usage Profile - RL78 Solar Energy Harvesting Demo -

Wireless Device Initialization

5.9mA x 3.36ms

Receive orTransmit with

Humidity Reading

29mA x 5.3ms

153uASec + 38.4uASec + 117.6uASec = 329uASec for Wireless Pulse

Radio In Sleep between Wireless Transmissions

5ua x 2 sec

10uASec

32mA x 1.2ms

29mA x 4.0ms

19.8uASec


Humidity Analyzer Block Diagram

RECEIVERTRansmITTER

Cymbet EH board

ZigBee Module

Humidity Sensor

Connector Board

ZigBee Module

Connector Board2xAA Battery

Rl78/L12 Display Board

RL78/G13 RL78/L12


RL78 – Low Power MCU Active Current: 144uA/MHz Standby Current: 0.57mA

(RTC + LVD) Stop: 220nA (RAM retained) 16-bit CISC, 41 DMIPS at

32MHz

Demo Components

Solar Panel Operating Voltage: 0.8V Output Current: 200μA@ 200Lux

2X Thin Film Battery Capacity: 100 uAh Pulse Discharge: 30 mA Voltage: 3.6V Operating Temp: 0 to 70C


Questions?


Technological advancements have made Energy Harvesting deployable today! Increasing efficiency of harnessing renewable energy sources New and creative energy harvesting resources being used Large number of ultra low power components (wireless MCUs)

introduced that make Energy Harvesting more commercially viable

Big leaps in battery technology Batteries today a lot smaller Now target applications where batteries were traditionally

Inconvenient to replace

‘Enabling The Smart Society’ in Review…

Renesas Electronics America

energy harvesting solutions - renesas electronics · determine energy available from your...

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