Low-power design in the age of IoT

Facilitating low-power designs for electronic devices is more important than ever before as we move toward a world dominated by the Internet of Things (IoT).

Essentially, the IoT refers a future scenario in which all types of electronic devices link to each other via the Internet. Today, it’s estimated that there are nearly 10 billion devices in the world connected to the Internet, a figure expected to triple to nearly 30 billion by 2020.

The challenge? Reducing power consumption (to extend battery life) while simultaneously maintaining acceptable levels of performance. Fortunately, Atmel has been focusing on low power consumption for more than ten years across its extensive portfolio of AVR and ARM-based microcontrollers and embedded microprocessors.

Design techniques employed to achieve the critical balance between power consumption and performance include:

• Use of hardware DMA and event system to offload the CPU
• Cut clock or supply on device portions not in use
• Careful balance of high performance and low leakage transistors
• Fast wake up from low power modes
• Low voltage operation

“With the Atmel picoPower technology found in our AVR 8-bit and 32-bit microcontrollers, we’ve even gone one step further. All picoPower devices are designed from the ground up for lowest possible power consumption – all the way from transistor design and process geometry, to sleepmodes and flexible clocking options,” an Atmel engineering rep told Bits & Pieces.

“Atmel picoPower devices can operate down to 1.62V while still maintaining all functionality, including analog functions. They have short wake-up time, with multiple wake-up sources from even the deepest sleep modes.”

Although certain elements of picoPower tech cannot be directly configured by the user, they do form a solid base that facilitates ultra-low-power application development without compromising functionality. On the user level, flexible and powerful features and peripherals allow engineers to more easily apply a wide range of techniques to reduce a system’s total power consumption even further. As expected, picoPower technology is also relatively simple to deploy, with both basic and advanced techniques reducing the power consumption of an application even further.

A perfect example of Atmel’s commitment to low-power devices is the 0.7V tinyAVR. Remember, a typical microcontroller requires at least 1.8V to operate – while the voltage of a single battery-cell ranges from 1.2V to 1.5V when fully charged, dropping gradually below 1V during use (yet still holding a reasonable amount of charge). This means the average microcontroller requires at least two battery cells.

“We have solved this problem by integrating a boost converter inside the ATtiny43U, converting a DC voltage to a higher level and bridging the gap between minimum supply voltage of the microcontroller and the typical output voltages of a standard single cell battery,” the Atmel engineering rep explained. “The boost converter provides the microcontroller with a fixed supply voltage of 3.0V from a single battery cell even when the battery voltage drops down to 0.7V.”

Simply put, this extends battery life by allowing non-rechargeable batteries to be drained to the minimum, while programmable shut-off levels above the critical minimum voltage level avoid damaging the battery cell of rechargeable batteries.

Interested in learning more about Atmel’s low-power, high performance portfolio? Be sure to check out our extensive ARM and AVR product lineups here.