A Temperature-Compensated Crystal Oscillator with Piecewise Polynomial Varactor Compensation Achieving ±3.75-ppm Inaccuracy from -30∘C to 90∘C
Journal
IEEE Transactions on Circuits and Systems II: Express Briefs
Date Issued
2021
Author(s)
Abstract
This paper presents a low-complexity temperaturecompensated crystal oscillator (TCXO). The frequency error compensation over temperature is realized by employing the proposed piecewise polynomial varactor (PPV). The PPV operation is determined by a temperature-dependent voltage generator. The temperature compensation is achieved without using an accurate mapping table and high-resolution data converters. In addition, an amplitude-control loop (ACL) is incorporated to maintain a stable XO operation under process, temperature, and supply voltage variations. This work is fabricated in a 180-nm CMOS process. The frequency inaccuracy of the proposed 40-MHz TCXO is ±3.75 ppm from -30 ∘C to 90 ∘C. Operating from a 1.8-V supply, the overall current consumption, including the proposed compensation and ACL, is 0.3 mA. IEEE
Subjects
amplitude-control loop (ACL).
Capacitance
crystal oscillator (XO)
Crystals
Generators
Resistors
Temperature distribution
temperaturecompensated crystal oscillator (TCXO)
temperaturecompensation scheme
varactor
Varactors
Voltage
Crystal oscillators
Error compensation
Amplitude control loops
Amplitude-control loop .
Crystal oscillator (XO)
Generator
Lower complexity
Piecewise polynomials
Temperature compensation
Temperature-compensated crystal oscillators
Temperaturecompensated crystal oscillator (TCXO)
Temperaturecompensation scheme
SDGs
Type
journal article