【摘要】 分析了LC压控振荡器(VCO)的相位噪声,提出了基于预稳压模块的低噪声低压差线性稳压器(LDO)结构,有效改善了电源噪声对LC VCO相位噪声的影响。设计了低噪声带隙基准电路和低噪声误差放大器,进一步优化LDO的输出噪声。通过调节反馈阻抗网络实现LDO输出电压可调,可以满足VCO的不同供电需求。通过改变滤波电容值,验证电源噪声对LC VCO的影响。采用0.35μm CMOS工艺进行了流片,测试结果表明,LDO在10 Hz~100 k Hz之间的输出均方根噪声电压为8.8μV,在-45~85℃温度范围内的温度系数约为43×10-6/℃;LC VCO输出频率范围为2.0~2.4 GHz,调谐范围为18.2%,相位噪声为-110.8 d Bc/Hz@100 k Hz,满足集成锁相环对LC VCO的噪声要求。更多还原

【Abstract】 The phase noise of the LC voltage-controlled oscillator（ LC VCO） was analyzed,and the structure of a low-noise low-dropout regulator（ LDO） based on a pre-regulation module was presented.The influence of the power noise on the LC VCO phase noise was improved effectively.The lownoise bandgap reference circuit and low-noise error amplifier were designed to further optimize the LDO output noise.The LDO output voltage can be adjusted by adjusting the feedback impedance network,which can meet the different power supply demands of VCO.By changing the value of the capacitance,the impact of power noise on LC VCO was verified.The proposed circuits were fabricated with a standard0.35 μm CMOS process.The measurement results show that from 10 Hz to 100 k Hz the root mean square output noise voltage of the LDO is 8.8 μV,and the temperature coefficient in the range of- 45- 85 ℃ is 43 × 10^-6/ ℃.The LC VCO exhibits a wide tuning range of 18.2% and low phase noise of-110.8 d Bc/Hz@100 k Hz from 2.0 GHz to 2.4 GHz,which meets the noise demands of the integrated PLL to the LC VCO.更多还原