The 32-bit EFM32 MCU from Energy Micro is the world’s most energy friendly microcontroller and is specially suited for use in low-power and energy sensitive applications, including energy, water, and gas metering, building automation, alarm and security, and portable medical/fitness equipment. Such applications need to operate for as long as possible (even decades) without external power or operator intervention. Battery replacement is often not possible for reasons of access and cost. Benchmarked against today’s ’top 10’ low power microcontrollers, the EFM32 Microcontroller has been proven capable of consuming a quarter of the energy required by 8-bit, 16-bit or 32-bit alternatives.
This can equate to extending the lifetime of a typical 3V coin cell battery by at least 300% or 7 years. In summary the microcontroller is characterized by very low active power consumption, reduced processing time, very fast wake-up time and ultra-low standby current. To achieve such characteristics, EFM32 has broken with microcontroller design convention in some very distinct ways:
1. Very low active power consumption
The energy friendly EFM32 microcontrollers have been designed to significantly reduce active mode power consumption. At 32 MHz and 3V the MCU only consumes 150 μA/MHz while running real life code.
2. Reduced processing time
Energy Micro has built the EFM32 Gecko microcontroller around the 32-bit ARM Cortex-M3
processor core. The Cortex-M3 architecture was developed for response and power sensitive applications and is much more processing efficient than 8- and 16-bit CPUs. Tasks are therefore executed with fewer clock cycles which dramatically reduces the active period.
3. Very fast wake-up time
EFM32 MCUs minimize the inefficient wake-up period between deep sleep modes and active mode
. This period simply cannot be neglected since low power systems continually switch between active- and sleep modes. EFM32 microcontrollers have reduced the wake-up time from deep sleep to 2 μs, ensuring as little energy as possible is used before the CPU starts processing its tasks.
4. Ultra-low standby current
EFM32 microcontrollers combine ultra low power technology with clever power management to reduce energy usage in standby modes while still performing basic operations. The Deep Sleep mode includes RAM and CPU retention
, Power-on Reset
and Brown-out Detection
safety features, and a Real Time Counter
while only using 900 nA. In Shutoff mode the consumption is only 20 nA.
5. Autonomous peripheral operation
In addition to lowest active and sleep mode energy consumption, the EFM32 peripherals
can operate in low energy modes without using the CPU. Using autonomous peripherals, an application can reduce power consumption while still performing very advanced tasks.
6. PRS - Peripheral Reflex System
The Peripheral Reflex System
in the EFM32 microcontrollers makes it possible to directly connect one peripheral to another peripheral without involving the CPU. With this system a peripheral can produce signals which other peripherals can consume and instantly react to while the CPU remains asleep.
7. Well architected Energy Modes
EFM32 microcontrollers have 5 efficient energy modes
which give system designers the flexibility to optimize their application for highest performance and longest battery life.
8. Energy efficient peripherals
EFM32 microcontrollers are packed with peripherals designed for low energy operation which increase the battery life 4 times compared to other low power 8-, 16-, and 32-bit solutions. Peripherals include:
9. LESENSE - Low Energy Sensor Interface
LESENSE provides a configurable and energy efficient way of controlling up to 16 external analog sensors without involving the Cortex CPU. This generic low energy sensor interface works in the 900 nA Deep Sleep mode and enables autonomous monitoring of virtually any type of analog sensor control scheme, including capacitive, inductive and resistive types. For example, LESENSE can be setup to intelligently monitor sensor values and take action via the peripheral reflex system (PRS) to wake up the CPU only if programmable thresholds are exceeded - recurring, energy wasting CPU wake-ups are not necessary.
10. Simplicity Studio and Advanced Energy Monitoring
Cuts design cycles in half: Simplicity Studio is a free and complete tools suite providing instant and "one-click" updated access to the latest datasheets, application notes, software tools, 3rd party IDE, code examples, demos and other EFM32 Gecko and EFR4D Draco resources. The Simplicity Studio console auto-configures in response to user preferences, and includes access to the unique energyAware Profiler and Advanced Energy Monitoring (AEM) data for creation of energy friendly software and real time energy debugging that works in conjunction with all Energy Micro starter and development KITs