STM32L - microcontroller with ultralow energy ...

STM32L - microcontroller with ultralow energy consumption 2 main parameters that are energy consumption in active and sleep modуs are usually taken into account while developing self-powered devices. It's due to different requirements for final applications. Application 1, for example, need constantly work in active mode consuming minimum energy. But application 2 consumes energy vice versa not in active but in deep sleep mode because the key targets are controller activation at rare intervals, execution of some actions and going to sleep. Taking these 2 parameters STMicroelectronics Company developed 32-bit ARM Cortex-M3 based STM32L microcontroller. STM32L line combines high productivity, code density characteristic for all ARM Cortex-M3 microcontrollers, low energy consumption in active and sleep modes. One of methods of reducing energy consumption in active mode is dynamical adjustment of voltage depending on necessary frequency of microcontroller timing. When microcontroller works with maximum frequency (for full usage of all capabilities -- productivity and peripheral) upper limit of power voltage should be 3-3.3 V. If you need switch a microcontroller to a mode of low clock frequency voltage will be excess and cause excess energy consumption costs. For this purpose STM32L line implemented a dynamic change in microcontroller core voltage. STM32L allows dynamic changing of core supply voltage in 3 ranges: 1.8 V (Range 1); 1.5 V (Range 2) и 1.2 V (Range 3). Such peculiarity helps to reduce common energy consumption in more than 25%. In range 1 (Range 1) you can reach maximum productivity without any restrictions. In range 2 (Range 2) maximum clock frequency is restricted with 16 MHz. In range 3 (Range 3) maximum controller frequency is restricted with 4 MHz. There are several capabilities for reducing common energy consumption that altogether allows us to significantly reduce microcontroller energy consumption -- to reduce supply voltage, switch off unused peripheral units clock, decrease clock frequency of microcontroller core and buses besides reducing energy consumption of microcontroller core. You can also switch off frequency-independent sources (clock, nonvolatile memory and voltage control sources) for reducing energy consumption. In general STM32L line has 7 modes of reduced energy consumption. •Sleep- a central processing unit is stopped but all ...