Low-Power Embedded Solutions
for IoT Sensor Nodes
By Alexis Alcott
Sr. Product Marketing Manager, MCU16 Division
Microchip Technology Inc.
Internet-Enabled Applications
IoT Sensor Node
2
IoT Sensor Nodes
Application Requirements

Low Power for Longest Possible Battery Life

Integrated Analog for Sensor Interface

Flexible Wireless Connection

Secure Data Transfer & Storage
3
Low Power MCU
MCU Run Power – 3 Factors
Power Mode
Clock Speed
Program Flow
5
MCU Power Modes
RUN
DOZE
IDLE
RAM
Retention
Mode
LVSLEEP
SLEEP
DEEP
SLEEP
µA
nA
mA
Core
Core
Core
Low
off,runs
V
off,
peripherals
Regulator
RAM
at slower
off
on run
speed,
Enabled,
Reset,
Most75%
peripherals
25%-65%
peripherals
90%
saved
Savings
saved
off
off
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MCU Clock Speeds

Frequency
32 MHz is 5 mA
 8 MHz is 1.3 mA
 1 MHz is 150 µA
 32 kHz is 26 µA

Spans
256 Hz to 32 MHz,
under software
control!
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MCU Program Flow

Utilize peripherals that can operate
while CPU is off (Idle)

ADC
 Comparators
 UART/SPI/I2C™
 PWMs
 Timers
Peripheral
Run
Mode
Idle
Mode
%
Saved(3)
ADC
520 µA
250 µA
52%
Comparator
340 µA
70 µA
79%
SPI
520 µA
250 µA
52%
Timers
320 µA
50 µA
84%
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Battery-Life Estimation
Without Power Modes

No Power modes

Battery life 47 days


Annoying!
Avg. Current 2.5 mA
www.microchip.com/batterylifeestimator
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Adopt New Modes

Sleep during sensor acquisition


Use Idle mode when communicating to radio


UART active, shut down core & Flash
Sleep during radio transmission



ADC runs in sleep
No MCU activity required
Wait to ensure transmission successful
Deep Sleep rest of time

Use RTCC to wake up 1 sec. later
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Battery-Life Estimation
With Power Modes

With Power modes

Battery life is 1 year

800% Increase!
Current Reduced 10X
 Sleeping for 1 minute
increases to 2 years

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Integrated Analog
Integrated Analog Peripherals

Easy Interface to Sensors



Benefits of Integration




Debugged noise and communication
Designer gets consistent analog performance across applications
Faster data path, reduced noise
Intelligent connections inside the chip
Simplify board designs, reduce board space
Lower-cost designs, faster time to market
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Without Intelligent Analog
ADC signal shielding increases board size
Multiple power planes for analog & digital
Complex routing for signals and shields
Noise coupled from USB to ADC
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With Intelligent Analog
Saved Board Area & Cost
Saved
Board
Area &
Cost
Routing, shielding, power planes integrated & debugged in chip
ADC, DAC, OpAmp, USB all integrated to MCU, lowers cost & space
Design simplified, throughput increased
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PIC24 “GC” Family

16-bit Sigma-Delta ADC



12-bit ADC






Analog control loops, stereo audio
Stimulus or thresholds
Operational Amplifiers


Ultra-high-speed data capture at 10 Msps
High-speed sensors, touch, communications
10-bit DACs


High dynamic range & high resolution
More information (3µV) eliminates need for amplifier
Analog control loops, Mic pre-amp, Signal conditioning
2.5 MHz Gain-Bandwidth, low power mode
Internal Analog Connection Switch Matrix
472-Segment LCD Driver with Voltage Boost
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Easy Prototyping –
Add Your Sensor

On-Board Sensors




Analog Header






Clean Analog Signals
Plugs Into Breadboards
Rich Display
Connectivity

PIC24F Intelligent Analog
Starter Kit
Part Number: DM240015
Light
Temperature
Touch
USB OTG, Host & Device
RF Module Footprint
Integrated Debugger
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Wireless Connection
Microchip Focus:
Wireless Connectivity of Things



Home health and Medical
Smart Power/Energy
Industrial Control and Monitoring
Home Control and Monitoring
Embedded products: low power, low free resource host processors
Get on the network, transfer data, and get off
Communicate with other things or users via Internet
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How to Connect?
Your Application!
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Embedded Wireless Portfolio
Protocol
Markets
Market
Driver
Network
Stack
Freq.
Embedded
Wi-Fi®
IEEE 802.11
Widespread
Commercial
Industrial
Internet
TCP/IP
2.4 GHz
Embedded
Bluetooth®
IEEE
802.15.1
Widespread
Commercial
Industrial
Smartphone
BT v2.1,
BT Audio,
BTLE
2.4 GHz
Embedded
Wireless
Proprietary
or IEEE
802.15.4
Vertical
HA, SEP,
Sensors
Cost
Local Network
MiWi™, BT,
ZigBee®,
RF4CE,
Sub 1 GHz &
2.4 GHz
Technology
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Microchip’s Bluetooth® Portfolio
RN41 / 41N
RN42 / RN42N
RN52
RN4020
Class 1
Bluetooth® 2.1
Class 2
Bluetooth 2.1
Class 2
Bluetooth 3.0
Bluetooth LE
Interfaces
UART / USB
Analog spk and mic,
i2S, SPDIF, PCM,
UART
UART
Profiles
SPP / HID / iAP / HCI
A2DP / ARVCP /
HSP / HFP / SPP /
iAP
GATT, Health,
Fitness, Proximity,
etc.; Custom data
Type
Power
Antenna
Size
Certification
3.3 VDC
ceramic on board
13.4 x 25.8 x 2.0
PCB
13.4 x 30 x 3.0
11.5 x 19.5 x2.0
BT SIG / FCC / CE / ICS
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Microchip’s Wi-Fi® Modules
MRF24WB0MA
MRF24WB0MB
MRF24WG0MA
MRF24WG0MB
RN171
RN131C/G
802.11 Radio
b
b/g
b/g
b/g
Tx Power
+10 dBm
+18 dBm
+12 dBm
+18 dBm
Power
Consumption
250 µA power save
85 mA Rx
150 max Tx
4 mA power save
95 mA Rx
240 max Tx
4 µA sleep
35 mA Rx
185 max Tx
4 µA sleep
40 mA Rx
200 max Tx
Antenna
u.FL / PCB
u.FL/PCB
RF pad
Chip/u.FL
Stack
On PIC® MCU
On PIC MCU
Integrated
Integrated
MCU Support
8/16/32 bit
PIC MCUs
8/16/32 bit
PIC MCUs
Any 8/16/32 bit
Any 8/16/32 bit
Certifications
FCC/IC/EN
Wi-Fi® Alliance
FCC/IC/EN
Wi-Fi Alliance
FCC/IC/EN
KC/NCC
Wi-Fi Alliance
FCC/IC/EN
KC/NCC/Telec
Wi-Fi Alliance
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Microchip’s ZigBee® & MiWi™
IEEE 802.15.4
MRF24XA
Low power
MRF24J40
MRF24J40MA
+0dBm
MRF24J40MD
+20dBm, PCB Ant
MRF24J40MC
+20dBm, Ext Ant
Sub-GHz
MRF49XA
433/868/915
MRF89XA
868/915/950
MRF89XAM8A
868 MHz (EU)
MRF89XAM9A
915 MHz (US,CA)
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Flexible Wireless Connection


Use the same MCU platform, as your wireless
connectivity needs change
Easy to interface to any PIC® MCU



UART or SPI
Easy daughter board to expand your PIC
MCU dev board ecosystem
Certified wireless modules


Speed development time
Faster product introduction
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Secure Data
PIC24F “GB2” Family



PIC24F “GB2” MCUs for Protecting Data in Embedded Applications

Hardware crypto engine (Industry standard AES, DES, 3DES)

Random Number Generator (RNG)

One-Time-Programmable (OTP) Key Storage
eXtreme Low Power Extends Battery Life

18 nA Sleep, 200 µA/MHz Run

Enabling Integrity of Data without Sacrificing Power Consumption
Connection to USB or Wireless Protocols

Integrated USB 2.0 Device, Host, OTG

Easy Connection to Certified Modules for
Wi-Fi®, ZigBee®, Sub-GHz, Bluetooth® LE
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Integrated Crypto Engine

Hardware Crypto Engine




Random Number Generator




Supporting True-Random and Pseudo-Random Numbers
Reach a Higher Level of Data Security
Reduces Possibility for Hacking
Secure Key Storage for Additional Protection




Industry Standards for AES, DES, 3DES
Encryption & Decryption & Authentication
Secure Data Transfer & Storage
512 bits OTP Key Storage
Once Written, Keys cannot be Read or Overwritten by Software
Stores up to 4 AES Keys or 8 DES Keys
Advantage of a Hardware Crypto over Software Implementation



Less Software Overhead Frees Up CPU Bandwidth & Memory
Operate at a Lower CPU Frequency to Save Power
Another Example of Microchip’s Core Independent Peripherals
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PIC24 “GB2” Block Diagram
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Application Example:
Remote Electronic Door Lock

Bluetooth®
Encryption for Security

LE RN4020

Near Field
Communication
(NFC)
Magnetic
Card

UART
Hardware
encryption/
Secure Key
storage
128KB
Flash
Key pad
control (touch)

PIC24FJ128GB204
CTMU
eXtreme Low Power

MCU
Core


Digital I/O
Display Unit
Low power extends battery life
Vbat with RTCC for battery backup
Access Options


Vbat
Uses Crypto, RNG & Key Storage
User data is encrypted
Secure key storage

Enter code manually via keypad
Magnetic keycard
Wirelessly via Smartphone
Power
Interrupt
Door Latch
Motor
Control Unit
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PIC24F “GB2” MCU Family
Low Power with Crypto Engine

Embedded Applications in the Internet-Connected World
Demand Secure Data & Long Battery Life

PIC24F “GB2” for Secure Data Transfer & Storage


Hardware Crypto Engine

Random Number Generator & Secure Key Storage
PIC24F “GB2” for eXtreme Low Power


Longer battery life for portable applications
PIC24F “GB2” for Easy Connection

Integrated USB

Easy interface to certified Wi-Fi® or Bluetooth® LE modules
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Summary
IoT Sensor Nodes
Application Requirements

Low Power for Longest Possible Battery Life

Integrated Analog for Sensor Interface

Flexible Wireless Connection

Secure Data Transfer & Storage
Note: The Microchip name and logo, and PIC are registered trademarks of Microchip Technology Inc. in the U.S.A. and other countries. MiWi is a trademark
of Microchip Technology Inc. in the U.S.A. and other countries. All other trademarks mentioned herein are property of their respective companies.
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