BANGALORE, INDIA: Microcontrollers (MCUs) are continuing to gain in popularity for portable, low power applications because they are easy to use, come in a wide range of configurations and can be used in many different applications.

This article will discuss the trends Texas Instruments sees for the future of microcontrollers, including smaller devices and a wider range of efficient processing with intelligent peripherals to reduce power consumption.

These advancements will enable designers to address trends within their own markets by utilizing the increased  memory and analog integration options to address system-on-chip (SoC) needs for battery-operated portable applications.

Key trends in the microcontroller market are the following.

* More energy efficiency
* Increased processing power
* Smaller form factors 
* More ease of use and ability to get to market faster
* More integrated features like RF and USB

Key MCU trend #1
Increased energy efficiency for longer battery lifetimes or energy harvesting

The market is demanding more efficient use of energy and longer times between battery recharge or replacement. This derives from several factors such as convenience to the end user, environmental concerns with battery disposal, but also a desire on the part of the end consumer to reduce energy consumption and their “carbon footprint”.

In some applications battery replacement is impractical or there are has a high labor costs and are requiring battery lifetimes of 20 years or more. One example of this is water meters where the meter must be located underground. Replacing the battery would involve digging up the meter which in colder climates are located one meter or more underground. This is a big expense as well as a huge inconvenience for all parties.

As consumer and industrial applications continue to become more sophisticated, their processing power and memory requirements are outpacing by far the progress made in battery capacity technology. In addition, consumers in today’s increasingly mobile world have ever-growing expectations for how long a device should operate before the batteries need to be changed or recharged.

The so called “Moore’s Law” stipulating that the area of a transistor decreases by 50 percent every 18 months, unfortunately, does not have a corollary for batteries. Although the progress for battery technology has been impressive over the past 10-15 years the technology adoption cycle which includes research, development, and end consumer acceptance is a much longer cycle than with silicon node changes which are largely transparent to the end consumer. This means that gains in battery lifetime must come from the silicon which must be more efficient at using that energy.
 
Another feature that is gaining a lot of traction and interest in the market is energy harvesting. This involves tapping into the ambient energy in the surrounding environment such as light, vibrations, or temperature and converting this into electrical energy.

Some of these sources have been utilized for years such as solar panels for converting sunlight into energy. However, for energy harvesting to be practical in many markets means that the silicon utilizing this energy must be highly efficient. For example, the energy that can be captured in most ambient vibrations is measured in milliwatts.

Even where there is abundant energy to be harvested such as solar, to be practical for portable equipment the MCU must be highly efficient so the energy harvesting unit is as small and lightweight as possible. The designer must also consider the case where the ambient energy is at a low point such as nighttime for solar power or low-traffic conditions for a bridge vibration monitor. Even applications where there is abundant energy such as a electrical meter, energy efficiency is a concern for brownouts or blackouts as well as reducing energy usage of the millions of meters connected to the power grid.