集成CMOS环形振荡器频漂补偿的实现

Implementation of Frequency Drifting Compensation for Integrated CMOS Ring Oscillator

为了提高CMOS环形振荡器的稳定度,以温度传感器作为检测电路,利用单稳态电路整形、滤波,把频率变化转变为电压变化对压控振荡器（VCO）进行负反馈调节,在温度变化和电源微小波动时,抑制了频率漂移。测试结果表明：CMOS环形振荡器输出频率为3.55 GHz,在温度区间-20~80°C内最差稳定度为2.45%,优于2.5%,达到射频识别系统中对频率稳定度的要求。

In order to improve the stability of CMOS ring oscillator,the temperature sensor is used as the detection circuit and the monostable shaping/filtering circuit is employed to changes from the frequency to the voltage and feedback it to voltage-controlled oscillator（VCO）.When the temperature and the power are fluctuations,the frequency drift is suppressed.Test results show that this CMOS ring oscillator′s output frequency is 3.55 GHz and within temperature range of-20 ~ 80 °C,the worst stability is 2.45%,better than 2.5% fitting the frequency stability for radio frequency identification system requirements.