← 返回 JSSC 论文列表JSSC 2022第4期Data Converters40nm CMOSDelta-Sigma ADCCrystal Oscillator
A 43 nW, 32 kHz, ±4.2 ppm Piecewise Linear Temperature-Compensated Crystal Oscillator With -Modulated
一种用于物联网的超低功耗温度补偿晶体振荡器，通过分段线性温度补偿实现高精度
32.768-kHz, ±4.2 ppm, 43 nW, 34 ppb Allan deviation
温度补偿晶体振荡器超低功耗物联网分段线性补偿脉冲注入驱动
▸创新点1：分段线性温度补偿技术（方法创新）。通过将复杂的温度调制曲线近似为分段线性元素，由粗粒度温度传感器选择，避免了传统精细查找表或多项式引擎的高功耗和大面积需求，显著降低了系统复杂度与功耗。
▸创新点2：脉冲注入晶体振荡器驱动（电路创新）。采用直接补充负载电容能量的脉冲注入驱动技术，支持两种不同负载电容状态下的稳定振荡，解决了传统连续驱动的高功耗问题，实现43 nW超低功耗。
▸创新点3：基于Delta-Sigma调制器的负载电容切换（系统创新）。利用Delta-Sigma调制器动态切换负载电容值实现温度补偿，仅需三点校准即可达到±4.2 ppm精度，相比现有技术校准复杂度降低8倍。
▸创新点4：混合信号温度补偿架构（系统创新）。结合模拟粗粒度温度传感器与数字分段线性补偿，在40 nm CMOS工艺下实现34 ppb Allan偏差底噪，兼顾精度与能效。
Abstract
This article describes an ultralow-power (ULP) temperature-compensated crystal oscillator (TCXO) with a pulsed-injection XO driver for IoT applications. Temperature compensation is achieved by changing the load capacitance ( C L ) between two values using a delta-sigma modulator ( /Delta1/Sigma1M). The complex modulation profile across temperature is approximated as piecewise linear elements that is selected by a coarse tempera- ture sensor. As a result, the power and area of fine-grain look-up tables (LUTs) or a polynomial engine used in prior works can be avoided. The proposed pulsed-injection XO driver that directly replenishes the energy of the C L sustains the XO oscillation for the two different CL states. Implemented in 40-nm CMOS, the proposed 32.768-kHz TCXO achieves an accuracy of ±4.2 ppm from −20 ◦Ct o8 5 ◦C with just three-point trimming and an Allan deviation floor of 34 ppb while consuming 43 nW, which is an approximate 8× improvement over the recent state-of-the-art TCXOs.