Cardes Fernando, Quintero Andres, Gutierrez Eric, Buffa Cesare, Wiesbauer Andreas, Hernandez Luis
Department of Electronics Technology, Carlos III University of Madrid, 28911 Leganes, Spain.
Infineon Technologies Austria AG, Villach 9500, Austria.
Sensors (Basel). 2018 Feb 3;18(2):445. doi: 10.3390/s18020445.
This paper analyzes the influence of phase noise and distortion on the performance of oscillator-based sensor data acquisition systems. Circuit noise inherent to the oscillator circuit manifests as phase noise and limits the SNR. Moreover, oscillator nonlinearity generates distortion for large input signals. Phase noise analysis of oscillators is well known in the literature, but the relationship between phase noise and the SNR of an oscillator-based sensor is not straightforward. This paper proposes a model to estimate the influence of phase noise in the performance of an oscillator-based system by reflecting the phase noise to the oscillator input. The proposed model is based on periodic steady-state analysis tools to predict the SNR of the oscillator. The accuracy of this model has been validated by both simulation and experiment in a 130 nm CMOS prototype. We also propose a method to estimate the SNDR and the dynamic range of an oscillator-based readout circuit that improves by more than one order of magnitude the simulation time compared to standard time domain simulations. This speed up enables the optimization and verification of this kind of systems with iterative algorithms.
本文分析了相位噪声和失真对基于振荡器的传感器数据采集系统性能的影响。振荡器电路固有的电路噪声表现为相位噪声，并限制了信噪比。此外，振荡器非线性会对大输入信号产生失真。振荡器的相位噪声分析在文献中是众所周知的，但相位噪声与基于振荡器的传感器的信噪比之间的关系并不直接。本文提出了一个模型，通过将相位噪声反映到振荡器输入来估计相位噪声对基于振荡器的系统性能的影响。所提出的模型基于周期性稳态分析工具来预测振荡器的信噪比。该模型的准确性已在130nm CMOS原型中通过仿真和实验得到验证。我们还提出了一种估计基于振荡器的读出电路的信噪失真比和动态范围的方法，与标准时域仿真相比，该方法将仿真时间提高了一个多数量级。这种加速使得能够使用迭代算法对这类系统进行优化和验证。
