ENERGY MICRO plans to win market share from established controller manufacturers with its 32-bit controller which is remarkable due to its extremely low power consumption. The controller operates with voltages between 1.8 V and 3.8 V and only consumes 180 µA per MHz in active mode, with this figure dropping to 0.9 µA, 0.6 µA and 20 nA in its various sleep modes.

ENERGY MICRO – a new manufacturer of microcontrollers?  What sort of company wants to dive headfirst into the shark tank that is the microcontroller market – a market which is not exactly lacking in occupants? Luminary Micro, the latest start-up company, did not enjoy a long and happy existence on its own which came to an end when it was swallowed up by Texas Instruments.
The new controllers from ENERGY MICRO feature the ARM Cortex M3 but manufacturers like TI, NXP and STMicro also use ARM cores to produce controllers with low power consumption levels. So what is the difference between them and ENERGY MICRO?

“We have developed the first really low energy controller architecture in the world”, says Geir Førre, the founder and CEO of ENERGY MICRO. Those who know Geir Førre also know that this statement is backed by more than just marketing. After all he also founded Chipcon and was CEO there from 1996 before he sold the company for around 200 million dollars to Texas Instruments in 2006. And he also had big plans for ENERGY MICRO which he founded in 2007. “By 2017 we want to hold a market share of 1 percent which would mean a turnover of 300 million dollars.” If we look at little more closely at Geir Førre’s market assessment he thinks that ENERGY MICRO could achieve a market share of 10 percent with its low energy controllers by 2017 even though Førre himself would never actually say so.

ENERGY MICRO has given its first family of new controllers the name Gecko. According to Førre the idea was quite straightforward because reptiles like the gecko only absorb 10 percent of the energy used by mammals. The ARM Cortex M3 core is renowned as being very frugal and that is one of the reasons why the new controller from the Norwegian manufacturer uses so little energy, but by no means the only one.

ENERGY MICRO has fitted the controller with a series of peripheral functions all of which share the low energy consumption feature. Førre is particularly proud of the LCD controller (4 x 40 segments) with an integral upwards converter. It allows users to configure the contrast, segment flashing and animations. However, whilst in use the controller only consumes 550 nA “less than the LCD controllers in clock chips”, says Førre. The 12-bit A/D converter uses just 200 µA whilst providing a conversion rate of 1 MSPS whilst a tiny 0.5 µA is all that is required for a conversion rate of 1 kSPS and a resolution of 6 bit. The integral temperature sensor achieves an accuracy of 1°C. The brown-out detector uses 100 nA. The 32 kHz real-time counter runs with 50 nA whilst the low energy UART requires 100 nA for its data rate of 9600 bit/s.

If the controller operates for 0.5% of the time in active mode and the wake-up intervals at 40 ms, a single 3 V lithium cell (CR 2032) could theoretically power the controller for a period of no less than 14 years. This value is a theoretical one because a battery of this type will hardly ever last for more than ten years. As a comparison we should consider that the same battery would be able to power the PIC24 from Microchip and the MSP320 from Texas Instruments for a period of around three and a half years. In addition, it would only manage to power the C8051 from Silicon Labs and the AVR from Atmel for around two years, the STM32 from STMi-croelectronics would run for 1.2 years whilst the LPC1100 and LPC1300 models from NXP would not even complete one full year.
In addition to the various low energy functions, the peripheral reflex system which is independent of the 32-bit bus makes a major contribution to the controller’s low power consumption level. For example peripheral functions can be switched on and off if necessary without the ARM core having to be active. The energy management unit can directly control the serial interfaces (USART, low energy UART, l2C), the I/O ports, the timers and triggers and the analogue functions (A/D and D/A converters, timers and watchdog).

Overall the controller can operate in five different modes. The highest current of 180 µA per MHz is consumed by the controller in active mode when all the functions are active. One level down from this (sleep mode) means that the ARM core is shut down whilst the flash program memory, RAM, DMA, the clock management, energy management and peripheral functions are active. In the other three sleep modes – deep sleep mode EM2 (RTC, POR and RAM data maintenance active): 0.9 µA, stop mode EM3 (power on reset and RAM data maintenance): 0.6 µA, shut off mode EM4: 20 nA – the other functions are shut down gradually until only power on reset and pin reset are active in shut off mode. The short wake-up time of 2 µs applies to the second and third sleep modes where the short time is particularly useful because the controller switches particularly frequently between these modes in most applications. “It is not about achieving low power consumption, but low power consumption over a period of time. That is why we always describe it as low energy”, says Førre.
For development tasks ENERGY MICRO has a development kit in its range which is fitted with an energy monitor. The developer can monitor power consumption in real time on a 320 x 240 pixel RGB LCD, thus enabling him to perfect the various usage conditions. “It is a very powerful tool which is the first of its kind in this form”, says Førre.

A low cost starter kit will also be available soon. This will enable users to display current power consumption on a PC.

ENERGY MICRO has already launched 22 versions of the EFM32G on to the market. The controllers operate in a temperature range from -40°C to +85°C and are enclosed in QFN32, QFN64, QFP100 and BGA12 housings. Versions with flash memories from 16 to 128 Kbyte and RAM from 8 to 16 Kbyte are available.
The company has also announced the launch of another family, the Tiny Gecko family, this year. In this case the low energy technology from ENERGY MICRO is transferred to even smaller housings with smaller memory sizes. ENERGY MICRO has also returned to its roots and is already developing RF chips which will use considerably less energy than all current RF solutions.

Please do not hesitate to contact us if you would like more information.

A01b