A Regulation-Free Sub-0.5-V 16-/24-MHz Crystal Oscillator With 14.2-nJ Startup Energy and 31.8- $\mu$ W Steady-State Power
A Regulation-Free Sub-0.5-V 16-/24-MHz Crystal Oscillator With 14.2-nJ Startup Energy and 31.8- $\mu$ W Steady-State Power
复制标题
具有 14.2nJ 启动能量和 31.8$mu$W 稳态功耗的免稳压低于 0.5V 16/24MHz 晶体振荡器
DOI：
10.1109/jssc.2018.2849012
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发表时间：
2018
影响因子：
5.4
通讯作者：
R. Martins
中科院分区：
文献类型：
--
作者：
Ka;Pui;M. Law;R. Martins
本文报道了一种免调节的低于 0.5V 的晶体振荡器 (XO)。 XO 专为蓝牙低功耗 (BLE) 无线电设计，旨在通过收集的能量直接供电。为了确保其性能免受工艺、电压和温度（PVT）变化的影响，同时减少其启动时间和能耗，我们提出了一种双模式 <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> 方案和可扩展的自参考线性调频注入（SSCI）技术。前者采用电感多级 <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> 来减轻启动期间晶体的杂散电容，但在稳定状态下采用单级 <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> 来保持相位噪声（PN）。对于后者 (SSCI)，我们生成一个可扩展的线性调频序列来启动 XO，避免调整辅助振荡器。采用 65 nm CMOS 制造的 XO 在 0.3 至 0.5 V 电源下使用两个常见晶体 (16/24 MHz) 进行测量。在 24 MHz 和 0.35 V 条件下，XO 的启动时间和能量分别为 400 <inline-formula> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> 和 14.2 nJ，同时显示出 31.8 <inline-formula> <tex-math notation="LaTeX">$\mu 的稳态功率\text{W}$ </tex-math></inline-formula> 和 1kHz 偏移时的 PN 为 -134 dBc/Hz。针对温度 (−40 °C–90 °C) 的频率稳定性为 14.1 ppm，针对电压 (0.3–0.5 V) 的频率稳定性为 17.9 ppm，均符合 BLE 标准 (±50 ppm)，并具有足够的余量。
This paper reports a regulation-free sub-0.5-V crystal oscillator (XO). The XO specifically designed for Bluetooth low-energy (BLE) radios aims for direct-powering by the harvested energy. To secure its performance against process, voltage, and temperature (PVT) variations, while reducing its startup time and energy, we propose a dual-mode <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> scheme and a scalable self-reference chirp injection (SSCI) technique. The former employs an inductive multistage <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> to mitigate the crystal’s stray capacitance during the startup, but a single-stage <inline-formula> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> in the steady state to preserve the phase noise (PN). For the latter (SSCI), we generate a scalable chirping sequence to kick-start the XO, avoiding trimming of the auxiliary oscillator. The XO fabricated in 65-nm CMOS is measured with two common crystals (16/24 MHz) over a 0.3-to-0.5-V supply. At 24 MHz and 0.35 V, the startup time and energy of the XO are 400 <inline-formula> <tex-math notation="LaTeX">$\mu \text{s}$ </tex-math></inline-formula> and 14.2 nJ, respectively, while showing a steady-state power of 31.8 <inline-formula> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> and a PN of −134 dBc/Hz at 1-kHz offset. The frequency stability is 14.1 ppm against temperature (−40 °C–90 °C) and 17.9 ppm against voltage (0.3–0.5 V), both conform to the BLE standard (±50 ppm) with adequate margin.