A high performance 19.2MHz digitally controlled crystal oscillator for NB-IoT

2018 3rd International Conference on Insulating Materials, Material Application and Electrical Engineering

材料科学;无线电电子学;电工学

Shi, Wenjie^1 ; Li, Xiaoqiang^2 ; Liu, Huimin^1 ; Wang, Wenshen^1,2

Tianjin Key Lab of Film Electronics and Communication Devices, School of Electrical and Electronic Engineering, Tianjin University of Technology, China^1

RF Microelectronics Corp., Tianjin, China^2

关键词: CMOS technology;    digital controlled crystal oscillator (DCXO);    Digital signals;    Digitally controlled;    Feedback principle;    Narrow bands;    Phase analysis;    Power supply voltage;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/452/4/042121/pdf
DOI  :  10.1088/1757-899X/452/4/042121

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

This design implements a 19.2MHz digitally controlled crystal oscillator (DCXO) for the narrow-band internet of things system (NB-IoTs). The paper uses positive feedback principle and phase analysis method to design the oscillator, and then the circuit is realized in a 55nm CMOS technology. The DCXO frequency is controlled by a capacitor matrix controlled by a 10bit digital signal. The results show that the crystal tunable range is more than 70ppm, with tuning step of 0.1∼0.2ppm. The phase noise in 1 KHz and 10 KHz offset were -137dBc/Hz and -159dBc/Hz, respectively. The maximum power consumption is 0.72mW at 1.2V power supply voltage, including an output buffer with 0.24mW power consumption.