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

被引：44

作者：

Chang, Yuyu ^{[1
]}

Leete, John ^{[1
]}

Zhou, Zhimin ^{[1
]}

Vadipour, Morteza ^{[1
]}

Chang, Yin-Ting ^{[1
]}

Darabi, Hooman ^{[1
]}

机构：

[1] Broadcom Corp, Irvine, CA 92617 USA

来源：

IEEE JOURNAL OF SOLID-STATE CIRCUITS | 2012年 / 47卷 / 02期

关键词：

AFC; analog buffer; capacitor tuning; CMOS crystal oscillator; DCXO; digital control oscillator; frequency pulling; phase noise; sine wave buffer;

D O I：

10.1109/JSSC.2011.2172673

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

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 26MHz 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 mm(2)

引用

页码：421 / 434

页数：14

共 13 条

[1] A digitally temperature-compensated crystal oscillator [J].