Transcript MCU Power Consumption

Energy Harvesting with
microcontrollers
Filip Dovland, Energy Micro
MCU Power Consumption
Energy = Power × Time
Active Mode
Power
Power
Time
Total energy
consumption
=
Active + Sleep
mode energy
Sleep Mode
Power
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Energy Modes
Energy Mode
Consumption
EM0 (Active Mode)
4.2 mA (@ 28 MHz)
EM1 (Sleep Mode)
1.4 mA (@ 28 MHz)
EM2 (Deep Sleep)
1 µA
EM3 (Stop Mode)
590 nA
EM4 (Shutoff Mode)
20 nA
Current Consumption for EFM32TG108
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Energy Harvesting
𝐼𝑆 − 𝐼𝑀𝐶𝑈
𝑑𝑉
=𝐶
𝑑𝑡
Sleep Mode
Active Mode
𝐼𝑆 > 𝐼𝑀𝐶𝑈
𝐼𝑆 < 𝐼𝑀𝐶𝑈
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Active vs Sleep Mode
Slope: 𝑑𝑉 = 𝐼𝑆 − 𝐼𝑀𝐶𝑈
𝑑𝑡
𝐶
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Adjust Clock Frequency
Frequency
Total
Normalized
28 MHz
4.2 mA
150 µA/MHz
21 MHz
3.2 mA
153 µA/MHz
14 MHz
2.2 mA
155 µA/MHz
11 MHz
1.7 mA
157 µA/MHz
6.6 MHz
1.1 mA
162 µA/MHz
1.2 MHz
0.25 mA
210 µA/MHz
Active mode current consumption EFM32TG108
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Control Time in Active Mode
 Supply Voltage Comparator (VCMP)
 Trigger interrupt on supply voltage threshold
 ISR used to wake up
or go to sleep
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Control Time in Active Mode
VCMP trigger sleep
VCMP trigger wakeup
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Backup Power Domain





Down to 20 nA
Available on GG, LG and WG
Optional 512 bytes of RAM retention and RTC
Battery can be charged during normal operation
Separate BOD thresholds
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energyAware Profiler
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