A Differential Digitally Controlled Crystal Oscillator With a 14-Bit Tuning Resolution and Sine Wave Outputs for Cellular Applications

Autor:	John Leete, Morteza Vadipour, Zhimin Zhou, Yuyu Chang, Yin-Ting Chang, Hooman Darabi
Rok vydání:	2012
Předmět:	Engineering Offset (computer science) business.industry Electrical engineering dBc Sine wave CMOS Phase noise Optoelectronics Digital control Electrical and Electronic Engineering business Crystal oscillator Electrical impedance
Zdroj:	IEEE Journal of Solid-State Circuits. 47:421-434
ISSN:	1558-173X 0018-9200
DOI:	10.1109/jssc.2011.2172673
Popis:	This paper describes the design topologies and considerations of a differential sinusoidal-output digitally controlled crystal oscillator (DCXO) intended for use in cellular applications. The oscillator has a fine-tuning range of ±44 ppm, approximately 14 bits of resolution, and an average step size of 0.005 ppm. All signals connecting externally to I/O pins are sine waves for reducing noise, interference, and spurs couplings. The 26 MHz DCXO fabricated in 65 nm CMOS achieves a phase noise of -149.1 dBc/Hz at 10 kHz offset measured at the sine wave buffer output. The DCXO is capable of meeting the stringent phase noise requirements for IEEE 802.11n 5 GHz WLAN devices. A typical frequency pulling of 0.01 ppm due to turning on/off the sine wave buffer is measured. The DCXO dissipates 1.2 mA of current, whereas each sine wave output buffer draws 1.4 mA. The DXCO occupies a total silicon area of 0.15 mm2 .
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::872461d5b90330be1cd2de85802b3fa3 https://doi.org/10.1109/jssc.2011.2172673 Zobrazit plný text záznamu