Lin CHuang YTSUNG-HSIEN LIN2022-04-252022-04-25202115497747https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122560921&doi=10.1109%2fTCSII.2021.3138774&partnerID=40&md5=21de271ce7891e72b948be4a3e8e91a2https://scholars.lib.ntu.edu.tw/handle/123456789/607322This 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. IEEEamplitude-control loop (ACL).Capacitancecrystal oscillator (XO)CrystalsGeneratorsResistorsTemperature distributiontemperaturecompensated crystal oscillator (TCXO)temperaturecompensation schemevaractorVaractorsVoltageCrystal oscillatorsError compensationAmplitude control loopsAmplitude-control loop .Crystal oscillator (XO)GeneratorLower complexityPiecewise polynomialsTemperature compensationTemperature-compensated crystal oscillatorsTemperaturecompensated crystal oscillator (TCXO)Temperaturecompensation scheme[SDGs]SDG7journal article10.1109/TCSII.2021.31387742-s2.0-85122560921