EFM32 Microcontrollers Energy Mode 2
Ultra Low Power Energy Mode 2

Energy Mode 2 - EM2

Advanced low power autonomous operation without CPU

In Energy Mode 2 (EM2), the EFM32 microcontrollers offer a high degree of autonomous operation while keeping the energy consumption at a very low level. The high frequency oscillator is turned off in EM2, but a 32 kHz oscillator is available for the low energy peripherals. The Real-Time Clock is also operative in this mode. Low power peripherals include:

  • LCD
  • Real Time Counter
  • Low Energy Timer - LETIMER™
  • Pulse Counter
  • Watchdog Timer
  • Low Energy UART - LEUART™
  • I2C
  • Analog Comparator

Despite that the ARM Cortex-M3 CPU is not running in Energy Mode 2, the microcontroller can perform advanced operations in this sleep mode. Peripherals run autonomously due to intelligent interconnection of peripherals and memory, and the wakeup time to Active Mode, Energy Mode 0, is only 2 μs. Low-leakage RAM ensures full data retention in EM2. The power consumption in EM2 is ultra low with only 0,9 µA.

Read more about the low energy features by selecting peripherals from the EFM32 block diagram below

ARM Cortex-M3 Memory System Debug Interface DMA Controller Clock Management Voltage Regulator Voltager Comparator Power-on Reset Brown-out Detector USART UART LEUART I2C External Bus Interface General Purpose I/O External Interrupts Timer/Counter Peripheral Reflex System Low Energy Timer Pulse Counter Real Time Counter Watchdog Timer ADC DAC AES LCD Controller Analog Comparator Peripheral Reflex System