Low power design for single battery powered applications
From the manufacturing process to all applications, very low power technologies are becoming an indispensable requirement in all designs. Energy-sensitive applications, especially those that require a single battery to operate for hours, require an ultra-low-power design concept. To meet these requirements, you must integrate the microcontroller, not only to understand the battery characteristics, but also to understand how to design a device in order to achieve continuous use for 10, 15 or even 20 years without the need to replace the battery.
To operate in very low power conditions, you must look at these very low power applications in a completely new way. Traditionally, these complex applications have analyzed their power usage in a more convenient way, proposing assumptions about the applications and power supplies used to generate "typical" power consumption.
However, for example, to achieve a single-cell powered application that can operate for 20 years, applications must draw less power than the battery's self-discharge rate, which makes the power per nA more critical in the overall power budget.
The industry standard CR2032 button battery has a self-discharge current of less than 250nA. CR2032 is a common lithium/manganese dioxide battery with a nominal (no load) voltage of 3.0V. In practical applications, to achieve the longest battery life, a highly integrated microcontroller (MCU) must be used. In sleep mode, the MCU must be able to operate well below 1μA while providing the correct mix processing capability and integrating peripheral and on-chip memory.
When the power consumption per nA is critical, it is no longer absolutely feasible to make assumptions about performance or power consumption. In order to evaluate the best choice for design, it is necessary to look at more parameters, although in some energy-sensitive applications, these parameters do not seem to be critical. For example, ultra-low-power microcontrollers for advanced sleep modes are now very common, however, the same sleep mode power consumption for a full range of microcontrollers may not be correct. The well-known family of microcontrollers is capable of exhibiting more than 1,700% change. Therefore, for ultra-low power designs, the focus is on the selected microcontroller family to upgrade memory without sacrificing low power performance, and the pins must be compatible.
As the demand for extremely low power designs grows steadily, the importance of an effective instruction set architecture (ISA) is increasing. Energy-sensitive applications are likely to be in sleep mode 99% of the time. Inevitably, these devices must be awakened periodically, at predefined intervals, or by external stimuli. In this regard, in order to achieve the task, the key consideration of design is the total amount of energy used. Design teams must choose microcontrollers that implement ISAs that have a larger percentage of single-cycle instructions to perform specific tasks, thus enabling tasks to be completed with shorter execution times and lower power.
The embedded electronics industry has reached a watershed in the construction of future applications, and the design, evaluation and practice of integrated components will be transformed. The significance of this shift is extraordinary, and more applications will incorporate extremely low-power technologies into their designs in the next few years.
This article is from Allicdata Electronics Limited.