Description

Ring oscillators (ROs) are popular due to their small area, modest power, wide tuning range, and ease of scaling with process technology. However, their use in many applications is limited due to poor phase noise and jitter performance. Thermal noise and flicker noise contribute jitter that decreases inversely with oscillation frequency. This paper describes a frequencyboost technique to reduce jitter in ROs. We boost the internal oscillation frequency and introduce a frequency divider following the oscillator to maintain the desired output frequency.