Regardless of the SoC architecture implemented in the edge device, energy efficiency is critical because the device is expected to function on a small battery for days without needing to be recharged.
Extending battery life is critical to IoT devices and for that reason, the SoC functionality is divided into blocks. One block that needs to be always-on such as voice activation, which makes reducing dynamic power important and other blocks that are idle for extended periods of time, which makes reducing static power important.
For additional power savings, the Bluetooth Smart is used because the protocol implements a low-duty cycle of operation, requiring minimal connection and re-connection time. Designers are implementing low-power design techniques such as clock gating, power gating, smart biasing and Dynamic Voltage Frequency Scaling (DVFS).
Foundry processes like 55-nm and 40-nm make use of finer pitch features that provide higher gate density, significantly lower power, and lower manufacturing cost, which are critical considerations for IoT applications. These processes also include ultra-low-power (ULP) features that enable very low-voltage operation and reduce leakage by offering ultra-high threshold devices.