The effects of supply-induced frequency variations on single-ended tuning $LC$ voltage-controlled oscillator (VCO) which degrade the jitter performance of the clock are investigated. The first-order impact on the supply sensitivity is that the varactor’s effective capacitance varies with the supply voltage, with other second-order impacts attributed to commonly used capacitive bank and cross-coupled pairs. A compensation technique based on complementary varactors to improve the supply sensitivity of single-ended tuning $LC$ VCO is proposed with no extra power dissipation, nor phase noise degradation within the relative frequency band of interest, along with the discussion on the operating principle of the compensation technique. Both the NMOS cross-coupled and complementary cross-coupled $LC$ VCOs have been designed, demonstrating robust supply-insensitive performance over process, voltage, and temperature (PVT) variations. Prototyped oscillators were fabricated in a 0.18- $\mu {\mathrm{ m}}$ CMOS process to verify both the theoretical analysis and the effectiveness of the proposed technique. Measurement results show that the compensated topologies exhibit more than 93% reduction in periodic jitter versus the noncompensated counterparts, with the figures of merit (FoMs) among the best compared with previous supply insensitive works.

中文翻译：

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具有互补变容二极管的低电源灵敏度 LC VCO

电源引起的频率变化对单端调谐的影响 $LC$ 研究了降低时钟抖动性能的压控振荡器 (VCO)。对电源灵敏度的一阶影响是变容二极管的有效电容随电源电压而变化，其他二阶影响归因于常用的电容组和交叉耦合对。一种基于互补变容二极管的补偿技术，以提高单端调谐的电源灵敏度 $LC$ 建议 VCO 没有额外的功耗，也没有在感兴趣的相关频带内降低相位噪声，同时讨论了补偿技术的工作原理。NMOS 交叉耦合和互补交叉耦合 $LC$ VCO 的设计在工艺、电压和温度 (PVT) 变化方面表现出强大的对电源不敏感的性能。原型振荡器以 0.18- $\mu {\mathrm{ m}}$ CMOS 工艺验证了理论分析和所提出技术的有效性。测量结果表明，与非补偿拓扑相比，补偿拓扑的周期性抖动降低了 93% 以上，与之前的电源不敏感工作相比，品质因数 (FoM) 名列前茅。