Engineering Ultra Low Power System on Chip Sensors

Engineering Ultra Low Power
System on Chip Sensors
Steve Grady – Cymbet
Scott Hanson – Ambiq Micro
Jim Magos – Cardinal Components
Key Trends Driving Micro SoC Sensors
Ultra Low
Power
Processors
Smart Devices
and
Sensors
Everywhere
Wireless is
pervasive
Integration
with
other
components
Miniaturization
Eco-Friendly
and
Renewable
Energy
Key Trends Drive New Technologies in Many Areas
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New innovative products are smarter, smaller and wireless
Smart devices with status indications
There will be billions of new networked smart devices
Industrial, Medical, Security, Transportation, Environmental...
EH-Powered Autonomous Wireless
Sensor Block Diagram
Sensor
(e.g., temperature,
pressure, occupancy)
Energy Harvesting Power Supply
ΔT
Motion
EM Field
Energy Manager
RTC/Timer
“Energy Aware”
Communications and
Control
Input
Power
Light
MCU + Radio
EH Transducer Electrical
Interface Discrete
Components
IC - Energy Conversion
Battery Management
Power Management
Rechargeable
Energy Storage
Device
System on Chip Sensors
Sensor Types
Oxygen Sensor
Hall Effect
Components
A to D
Position Sensor
D to A
Micro-C
Seismometer
Micro-P
Soil Moisture
Speed Sensor
Water Sensor
Particle
Air Speed
Inclinometer
RTC
TCXO
Altimeter
VCXO
GPS
Depth Gauge
FPGA
Accelerometer
Crystal
Solid State Battery
Gravimeter
Gyroscopic
Level Shifter
Bluetooth
EEPROM
Multiplayer
Encryption
Trends Driving Need for Innovative Energy Storage
TRENDS
Ultra Low
Power
Processors
Smart Devices
and
Sensors
Everywhere
Wireless is
pervasive
Integration
with
other
components
Miniaturization
Eco-Friendly
and
Renewable
Energy
CURRENT SOLUTIONS
Bulky Size/Metal “coin” package
Cannot be integrated with other electronics
60 mm
wireless
devices
annually
Complete
10 year
HP: 1 Low
energy for
Space used
800mm
Micro
wireless component
Solar powered
trillion
machines
in
a
- Toxic Chemicals
sensorssensor with s Pennies
sensors Not
in Eco-Friendly
package
power
to dollars
5 years Transportation Safety Issues
Rechargeable solid State Batteries
EnerChips on
Silicon Wafers
Protective Coating
Solid State Cathode
Current Collector
Solid State Electrolyte
Charging
Discharging
• EnerChip™ Rechargeable Solid State Batteries are created on Silicon
wafers using standard semiconductor fabrication processes and device
packaging techniques
• As the battery is charged, ions move from the cathode through the solid
electrolyte to the current collector. As the battery discharges, the
reverse is true.
• EnerChips are 150 microns thick – less than two human hairs – and are
1/20th the thickness of a comparable battery.
Key Technical Battery Requirements
High Cycle Life
Flat Output Voltage Profile
Capacity with Cycling
70
60
Capacity (µAh)
50
4.2V
4.15V
40
4.1V
4.3V
30
4.0V
20
10
0
0
100
200
300
400
500
600
700
800
900
1000
Discharge Cycle #
Fast and Simple Charge
Low Self-Discharge
Charge Current & Charge Capacity vs, Charge Time
Percent of Charge
3.5
3.0
80
2.5
60
2.0
1.5
40
1.0
20
0.5
0
10
20
30
Time (Minutes)
40
50
60
0
15
14
Charge Loss %
4.0
100
0
Self-Discharge
4.5
Charge Current/ Battery Capacity
120
13
12
11
Non-Recoverable
10
9
8
7
6
Recoverable
5
4
3
2
1
0
1
2
3
Stand Time (Years)
4
5
Solid State Batteries are Safe
Assembly, Transport, Use and Disposal
Rechargeable solid state batteries are the only energy storage solution that satisfies all
the following global environmental and safety regulations and certifications:
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RoHS
China RoHS
REACH
CE Mark
UL - Underwriters Laboratory
JEDEC IC Packaging Standards and Tape and Reel EIA Standards
IEC, NEMA/ANSI
United Nations Transportation Air Safety Regulations
WEEE Waste Electrical and Electronic Equipment Directive
EU Battery Directive
MSDS and OSHA Information
Solid State Battery End-of-life Disposal Instructions
In vitro/In vivo Biocompatibility Test Standards for Cytotoxicity
Packaging Options
Side-by-Side EnerChip and ICs with Wire Bond
 Solid State Batteries are a unique solution
for customer applications requiring a small
energy storage device integrated directly
into the system
 EnerChips support many different device
configurations using standard wire bond or
solder bump attachment
 Applications in the this market include:
Stacking EnerChip and ICs using Wire Bond
EnerChip Bare Die
µController, Sensor, RTC
Stacking EnerChip and ICs using solder bump Flip Chip
• Sensor Systems on Chip
• Security and tamper detection devices
• Electronic fuses for various devices
• Medical devices – ophthalmic, implantable,
patches
EnerChip and ICs in System On Chip
Sensor SoC Packaging Roadmap
EnerChip Solid State Batteries in Bare Die form are the ideal devices for integrating energy storage in
emerging System in 3D Packaged Systems EnerChips using wire bonding, solder bumps for flip chip
or eventually Thru Silicon Vias can be integrated into Systems in Package, Package on Package, TSV
stacks and other 3D configurations
EnerChip Bare Die Location Examples
Solving the Power Problem
System Software Architecture
System Hardware Architecture
Hardware Components
The focus of
today’s
presentation
Power must be optimized all levels of the design hierarchy
Conventional
Super-threshold
Voltage
Threshold Voltage
(i.e., Noise Floor)
Sub-threshold
Voltage
Building ULP Components with Sub-threshold
Threshold Voltage
(i.e., Noise Floor)
Time
Sub-threshold enables energy reductions on the order of 1.82/0.52=13X
The Limits of Sub-threshold
Inverter Operation at 65mV
SRAM Cell Operation at 70 mV
Deep sub-threshold operation is possible, but significant
challenges exist
The Challenges of Sub-threshold
1E-4
Vdd=1.2V
Ion/Ioff~800,000
1E-5
ID (A)
1E-6
1E-7
Vdd=250mV
Ion/Ioff~800
1E-8
1E-9
1E-10
1E-11
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Vgs (V)
On-to-off current ratio is reduced dramatically
The Challenges of Sub-threshold
1E-4
1E-5
ID (A)
1E-6
Limited Vth sensitivity
at high Vdd
1E-7
1E-8
1E-9
~14X change in current
for ∆Vth=100mV
1E-10
1E-11
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Vgs (V)
Current is exponentially sensitive to process, voltage, and temperature
Addressing the Challenges with SPOT
2012
processor
244µm
122µm
memory
305µm
181µm
2005
2006
2007
2009
2010
• SPOT: Sub-threshold Power Optimized Technology
• Standard manufacturing process
• Circuit, architecture, and test methodology that
enables robust sub-threshold operation
• Proven over 8 years of development
AM18XX: A SPOT-Based RTC
VCC VBAT
nCE
SDI
SCL
SDA/O
Power
Control
Analog
Compare
I2C/SPI
Interface
Calibration Engine
XO
100ths
Seconds
Minutes
Hours
Days
Weekdays
Months
Years
Alarms
XT Osc
Divider
RC Osc
Divider
Timer
WDT
XI
Control
RAM
WDI
EXTI
nEXTR
Int/Clock
Reset
FOUT/nIRQ
PSW/nIRQ2
nTIRQ
CLKOUT/nIRQ3
nRST
VSS
SPOT enables unprecedented power of only 15-55nA
A Typical Use Case
SPOT enables a 5X increase in battery life
VDD
VOUT
VCC
VBAT
VCC
I2C/SPI
EnerChip with
Integrated Power
Management
+
AM1805
RTC
XO
nIRQ
MCU
_
IRQ
XI
VSS
VSS
VSS
Incumbent System
SPOT-Based System
EnerChip Power
Management Current
35nA
20nA
RTC Current
150nA
21nA
Life for 12µAh battery*
4 days
20 days
* EnerChip CBC012 battery under 41nA load is an 18uAh equivalent
Sensor SoC - What’s Needed?
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Looking for reduction in system size
Systems incorporating energy harvesting techniques
Low power small wireless systems
Wireless sensor nodes
Short time back up power
Self powered systems
Embedded power systems needing time logs, datalogs
Embedded processing systems
Any system that maintains RTC during power outage
Real Time Plus Concept
Integration
Real Time Clock
Solid State
Battery
Configuration
Options
Battery
Recharging
Circuit
I2 C
RTC
Crystal
Real Time Plus – RTC + Battery + XTAL
Traditional Design Approach
Real Time Plus Solution
78% smaller surface area
Type
Length Width Square mm Area
PCB with CR2032
30.0
32.0
960
CRTP
12.4
17.4
216
78%
RTPlus SoC Components
Real Time Clock
Temperature Compensation
Industrial Temperature Range -40 to +850C
RoHS Complaint
Calendar tracks year and leap year
Clock tracks seconds, minutes and hours in 24 hour format
Interrupt Output
Programmable Alarm and Universal Timer
Extremely Accurate i.e., @250C, + 2 PPM
8 Bytes of Ram and 2 Bytes EEPROM for Customer Application
Battery
Solid State Battery
RoHS Compliant
Rechargeable with on board trickle
charge circuit
Package
Application Examples
Wireless sensors and RFID tags
Consumer appliances
Energy Harvesting
Time Keeping
Metering
Telemedicine
Time stamping
Smart energy
Military surveillance
High quality Crystal
I2C Interface Bus
SMD
10.3 x 12.7 mm
12.4 x 15.1 mm
12.4 x 17.8 mm
CRTP Series Power Holdover

CRTPN05 4 days
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CRTPA12 20 days
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CRTPA50 90 days
Creating a Sensor SoC – Modu-FlexTM Example
Typical System Before Modu-FlexTM
After Modu-FlexTM
Sensors
Battery
Backup
Recharging
Circuit
Modu-Flex
Analog Processing (ADC)
P
O
W
E
R
Micro P,
or
Micro C
Memory
Analog Processing (ADC)
RTC
Crystal
Control Logic
Oscillator
Analog Processing (DAC)
Output Driver, switches
P
O
W
E
R
Micro P,
or
Micro C
Memory
Control Logic
Analog Processing (DAC)
Output Driver, switches
Sensor SoC Package Innovation
uC
Crystal
RTC
EEPROM
Osc
Battery
uC
Charge
Temp
Sensor
D/A
A/D
Output
Driver
Switch
Sensor SoC Integrated Package
Modu-Flex is a RoHS compliant (including the battery), CMOS low-power, real-time
clock/calendar module with built-in Thermometer, Digital Temperature
Compensation circuitry (DTCXO), a solid-state battery back up for the
RTC, and single or dual output oscillator circuit (1 to 200 MHz)
Real Time Clock—High Accuracy 2 PPM
TCXO Crystal
Applications:
• Automotive:
Solid State Battery
Re-charging circuit
Oscillator single output
• Metering:
• Outdoor:
Temperature Sensor
I2C Flexibility
CRTP
Modu-Flex
Car Radio / GPS and Tracking
Systems / Dashboard / Engine
Controller / Car Mobile &
Entertainment Systems / Tachometers
E-meter / Heating Counter
ATM & POS systems / Surveillance &
Safety systems / Ticketing systems
• All Types
Portable and battery operated devices
• Industrial Automation, Robotics, Controls
• Consumer
Gaming, Set top box, Data Storage
• White goods Refrigerators, Dishwasher, Washers
Benefits:
Integration, any frequency from 1 to 200 MHz, small
physical size, simplifies design, custom options available,
factory configurable in 48 hours
Sensor SoC Creation Process
Customer
Concept
Design
Flexible
Manufacturing
Integrated
Solution
Prototype-Small Volume
Flip Chip
Item
Conformal
Plastic
Mold
Coating
Wire Sweep
Die 2
Die 2
Epoxy 2
Die 1
Base with
Epoxy
1 gold
termination
Stack Die
Hard PCB
Flex PCB
Hard PCB
Volume Packaging
Customizable System Options
Customizable System Options
Continued
Touch Sensing
• CapSense capacitive sensing
(buttons, sliders)
• Touchscreens
• Trackpads
• Proximity sensing
Other sensing
• Position
• Accelerometer
• Water
• Speed
• Inclinometer
• UV
• Pressure
Fan/Motor Control
• AC motor
• DC motor
• Fan
• Fuel pump
• Instrument gauges
DACs
• 6-, 8-, and 9-bit
• 6- and 8-bit multiplying
Filters
• 2-pole low-pass
• 2-pole band-pass
• Modulators
• Peak detectors
Amplifiers
• Programmable gain
• Instrumentation
• Comparators
Timers/Counters
• 8-, 16-, and 24-bit
Pulse-Width Modulators
• 8-, 16-, and 24-bit
Coming soon
GPS
Bluetooth
Zigbee
IrDA
Modu-Flex is a flexible module that Integrates
peripherals into a single component
A fast, reliable way for companies to take their design
and integrate for production with a low NRE custom
offerings and solutions.
Combining IC Bare Die into SoC
Cymbet EnerChip RTC CBC34803 example
AM0803
• Integrate Ambiq AM0803 (I2C)
with Cymbet EnerChip CBC005
and CBC910 power mgmt IC
• Miniature Land Grid Array
(LGA) module or possibly BGA
package
• Wire bond in this case, but
could also use flip chip style
attachment using bumped
bare die
• CBC34813 uses AM0813 (SPI)
RTPLUS and EnerChip RTC
Integrated Solutions Examples
Ambiq RTC + 5uAh EnerChip +
PMIC + Xtal Oscillator using
Packaged parts – 8 mm x 10 mm
Ambiq RTC + 5uAh EnerChip + PMIC
using bare die – 5 mm x 5 mm
Summary
• Key Industry Trends and Application Requirements
are driving the need for highly integrated Sensor
Systems on Chip designs
• Ultra-low power electronics with Sub-threshold
Power Optimized technologies are now available
• Solid State Batteries provide ideal energy storage
• Innovative packaging techniques enable optimized
footprint and volume
• Optimized Sensor SoCs are available today