Sleep modes and idle modes in general-purpose microcontrollers have allowed embedded processors to reduce real-time energy consumption and tackle many battery- and low-powered designs. However, as embedded systems become increasingly complex, it takes additional logic to implement a denser, more sophisticated micro core as well as the higher-end peripherals we expect to see today.
As a result, even in standby modes, static power draw can be an issue when trying to reduce energy, especially if long sleep times are required.
One factor in reducing energy and extending run-time is operating voltage. While many 5 V systems are still around and supported, the majority of designs today have migrated to the 3.3, 2.5, and 1.8 V arenas. With voltage being directly proportional to power draw, you can see that a static 5 V system will burn almost three times the power of a 1.8 V system. This is even more the case with switching circuits, since power draw is also proportional to switching frequency. This article examines 8-bit microcontrollers with simpler architectures and lower-than- average voltage cores that can operate under 1.8 V. While these levels may not work with most external peripherals, it does allow lower power, long-term sleep/hibernation modes that can extend battery life to its limits.
Read More: 8-bit MCUs That Can Operate Under 1.8 V