Date: 21/06/2010

ST's ultra low power MCU cousins

In designing energy efficient systems microcontrollers (MCUs) play important role. But how much power does the MCUs consume while controlling? Well, today's MCU operate by consuming fraction of a milli amp (200 -300 micro amps) in full active mode and in stand by mode; its less than 1 micro amp. Combined with today's energy harvesting devices MCUs can work without any external power source.

Here is one such family from ST Microelectronics which work at such a low power.

ST's energyllite family includes both STM8L and STM32L family. ST has built these devices using ultra low leakage technology.

The processor used in STM32L family is ARM Cortex -M3. The other features available in this family includes 3 UART, 2 SPI, 2 I2C peripherals, 8 16-bit timers, 2 watchdog timers, 2 comparators and a temp sensor. The power performance goes like this, 185 micro amps/DMIPS. ST says this is double the performance compared to closest competitor. STM32L MCUs work in 6 different power modes. This family has internal RC oscillator, features Optimized run mode, and a host of security and safety features.

The 8-bit STM8L microcontroller family consume less than 400nA of static power and 150µA/MHz of dynamic current. STM8L also works in different power modes and the device jumps from halt to active mode within 4µs supporting frequent use of the low-power mode. The peripherals packed include the sub-1µA RTC and Automatic Wake-Up (AWU).

The suggested application of these MCUs are broad which includes Portable Medical instruments, E-metering systems, Alarm system, industry automation, mobile gadgets, and sensor systems.


To know more visit www.st.com/stm32l
and www.st.com/stm8l