Top 10 Silicon Labs 32-bit Microcontroller Technology Features

Silicon Labs' EFM32™ 32-bit microcontroller (MCU) family 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. Since battery replacement is often not possible for reasons of access and cost, such applications need to operate for as long as possible without external power or operator intervention. Silicon Labs' energy friendly EFM32 32-bit microcontrollers beat existing low-power MCU alternatives — here we'll highlight the 10 factors that make this possible.

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Very Low Active Power Consumption

The energy friendly EFM32 microcontrollers have been designed to significantly reduce active mode power consumption. At 32 MHz and 3 V the MCU only consumes 150 µA/MHz while running real life code.

Reduced Processing Time

Silicon Labs has built the EFM32 microcontroller family around the 32-bit ARM® Cortex®-M processor core. The Cortex-M 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.

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.

Ultra-low Standby Current

The EFM32 combines 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.

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.

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.

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.

EFM32 with 3 V power supply.
Real application from memory.
Run Mode
Sleep Mode
Deep Sleep
Stop Mode
Shutoff Mode
Current Consumption Down to 63 µA/MHz Down to 32 µA/MHz Down to 0.9 µA Down to 0.6 µA Down to 20 nA
Wake-up Time - 0 2 µs 2 µs 160 µs
Wake-up Events Any Any 32 kHZ Peripherals Async IRQ,
12C Slave
Analog Comparators
Voltage Comparators
GPIO Rising/Failing Edge
CPU (Cortex-M3/M0) On - - - -
High Frequency Peripherals Available Available - - -
Low Frequency Peripherals Available Available - - -
Asynchronous Peripherals Available Available Available Available -
Full CPU and SRAM Retention On On On On -
Power-on Reset/Brown-out Detector On On On On On

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:

  • LCD controller driving 4 x 40 segments at only 0.55 µA
  • Low Energy UART, full communication at 32 kHz while consuming only 100 nA
  • 12-bit ADC performing 1 million samples/sec at only 350 µA
  • Analog Comparator using as little as 150 nA
  • Hardware accelerator for 128/256-bit AES encryption and decryption in only 54/75 cycles

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 PRS to wake up the CPU only if programmable thresholds are exceeded – recurring, energy wasting CPU wake-ups are not necessary.

Simplicity Studio and Advanced Energy Monitoring

Simplicity Studio is a complementary tools suite providing instant and "one-click" updated access to the latest data sheets, application notes, software tools, 3rd party IDE, code examples, demos and other EFM32 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 Silicon Labs EFM32 starter and development kits.

32-bit Microcontroller Families

View our extensive 32-bit microcontroller portfolio