A Temperature Compensated Ring Oscillator With LC-Based Period Error Detection

• Published in: IEEE transactions on very large scale integration (VLSI) systems Vol. 31; no. 12; pp. 2152 - 2156
• Main Authors: Bae, Seongun, Lee, Minseob, Yoo, Sang-Min, Sim, Jae-Yoon
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Calibration; Codes; Control theory; Digital frequency-locked loop (FLL); Error detection; Feedback loops; frequency reference; Oscillators; Polynomials; Power consumption; Resonant frequency; Resonators; ring oscillator; Ring oscillators; Temperature measurement; Temperature sensors; temperature stability; trimming
• ISSN: 1063-8210; 1557-9999
• DOI: 10.1109/TVLSI.2023.3322709

This brief presents a hybrid oscillator architecture that combines an <inline-formula> <tex-math notation="LaTeX">LC </tex-math></inline-formula> resonator and an inverter-based ring oscillator to exploit the inherent benefit of an <inline-formula> <tex-math notation="LaTeX">LC </tex-math></inline-formula> resonator for frequency accuracy with low power consumption. This architecture uses the period of the <inline-formula> <tex-math notation="LaTeX">LC </tex-math></inline-formula> resonator as a reference time to control the period of the ring oscillator through a feedback loop. By intermittently turning on the <inline-formula> <tex-math notation="LaTeX">LC </tex-math></inline-formula> resonator for the period error detection, its power consumption could be reduced to a reasonable level while benefitting from its frequency accuracy over environmental variations. The implemented oscillator in a 40-nm CMOS process achieves a temperature sensitivity of 7.65 ppm/°C in a temperature range of −20 °C-80 °C after two-point batch calibration with a second-order polynomial. A period jitter shows 2.44 psrms with an output frequency of 98 MHz.