An RC Oscillator With Comparator Offset Cancellation

作者：Paidimarri Arun^*; Griffith Danielle; Wang Alice; Burra Gangadhar; Chandrakasan Anantha P

来源：IEEE Journal of Solid-State Circuits, 2016, 51(8): 1866-1877.

DOI：10.1109/JSSC.2016.2559508

• Allan deviation
• Allan variance
• crystal replacement
• guard time
• offset cancellation
• RC oscillator
• Schmitt trigger
• startup time
• temperature stability
• timing accuracy

A fully-integrated 18.5 kHz RC time-constant-based oscillator is designed in 65 nm CMOS for sleep-mode timers in wireless sensors. A comparator offset cancellation scheme achieves 4x to 25x temperature stability improvement, leading to an accuracy of +/- 0.18% to +/- 0.55% over -40 to 90 degrees C. Subthreshold operation and low-swing oscillations result in ultra-low power consumption of 130 nW. The architecture also provides timing noise suppression, leading to 10x reduction in long-term Allan deviation. It is measured to have a stability of 20 ppm or better for measurement intervals over 0.5 s. The oscillator also has a fast startup-time, with the period settling in 4 cycles.

• 出版日期2016-8