摘要
描述了一种射频芯片内数控晶体振荡器(DCXO)的振荡主电路设计,以Deep-N-WellCMOS工艺的PMOS为主工作管,采用Santos(改进Colpitts)结构、非对称差分式振幅控制环,避免了因Vt依赖工艺与温度等而产生的可靠启振问题。该10MHz DCXO振荡器主电路,采用TSMC Mixed/RF 0.18μm CMOS工艺,在2V电源电压下,仿真得到输出特性为:振幅峰峰值0.8V,平均电流2.9mA,相位噪声-140dBc/Hz@1kHz,-173dBc/Hz@1MHz,启动时间约2.8毫秒,可作为DCXO核心振荡模块。
This paper introduces an oscillating circuit with Vt independent automatic amplitude control loop. It adopts Santos architecture, asymmetric differential pair, current subtraction technique and so on. The simulation in Cadence Spectre RF using TSMC 0.18μm CMOS process shows that the phase noise is-173dBc/ Hz@ 1MHz,-140dBc/Hz @ 1kHz. The peak-to-peak oscillation amplitude is 0.8V and average current consumption is 2.9mA under 2V supply while start-up time is about 2.8 milli seconds.
出处
《信息技术》
2008年第4期81-83,96,共4页
Information Technology
关键词
晶体振荡主电路
自动振幅控制
相位噪声
oscillating circuitry for crystal oscillator
automatic amplitude control loop
phase noise
