带自动振幅检测控制的皮尔斯晶体振荡电路设计

A Pierce crystal oscillator circuit with amplitude regulation

本文描述了一种工作在射频芯片内的晶体振荡电路,基于对3种传统结构晶体振荡电路的分析,采用皮尔斯晶体振荡电路,以CMOS工艺的NMOS为主振荡管,实现了高稳定、低相位噪声输出的振荡信号,电路带有自动振幅检测及控制功能。该16 MHz皮尔斯晶体振荡器采用TSMC0.18μm CMOS工艺实现,当电源电压为1.8 V时,电路仿真特性如下:输出信号振幅峰峰值约为0.5 V,工作电流约为0.46 mA,相位噪声为-127.8 dBc/Hz@1 KHz,-163 dBc/Hz@1 MHz,振荡器起振时间约为1.5 ms。

The paper introduces a crystal oscillator circuit embedded in RFIC. Based on the analysis of the conventional crystal oscillator,the oscillator circuit employs Pierce structure with amplitude regulation circuit. Implementing with TSMC 0.18 μm CMOS process in Cadence Spectre RF,the simulation results shows that: the output peak-to-peak oscillation amplitude is about 0.5 V and the average current consumption is 0.46 mA under 1.8 V power supply;the phase noise is-127.8 dBc/Hz@1 KHz,-163dBc/Hz@1M Hz while the start-up time is about 1.5 ms.