Ultra-Low Power Relaxation Oscillators survey: Design Trends and Challenges

The Relaxation oscillators (ROSCs) offer a better trade-off between power consumption, physical area and accuracy. This paper presents a study of recently published ultra-low-power relaxation oscillators with low-temperature coefficient, identifying its characteristics, performance parameters, and main challenges. A brief review show as state-of-the-art circuits handle with PVT (Process, voltage, and temperature) variations. By the end of this analysis, some trends in relaxation oscillators design are discussed.