柔性电子中参数性故障检测的频谱特征
Spectral Signatures for Parametric Fault Detection in Flexible Electronics
中文总结 AI 辅助
针对柔性电子中参数性故障，提出基于VCO频谱能量的频域测试特征电路，以轻量模拟滤波器提取RMS谐波特征，实现无ATE现场测试，面积功耗显著降低。
中文摘要 AI 辅助
基于氧化铟镓锌（IGZO）单极性薄膜晶体管（TFT）技术的柔性电子（FE）可实现用于可穿戴传感、生物医学监测和人机界面的轻量级适形系统。这些应用依赖于模拟和混合信号（AMS）模块，这些模块必须在关键挑战下保持准确性：低成本单极性制造导致的器件变异性增加；由于缺乏刚性封装而容易发生制造后故障；参数性故障在无硬数字故障的情况下降低模拟精度；以及用于一次性FE系统的专用自动测试设备（ATE）的高成本和现场不可及性。依赖模数转换器（ADC）的传统测试方法在资源受限系统中带来过大的面积开销；关键是，ADC的准确性本身受工艺、电压和温度（PVT）变化的影响，导致测试失效。本工作提出一种频域测试特征电路，利用压控振荡器（VCO）的频谱能量来检测被测AMS电路中的故障和参数偏差。VCO将故障引起的控制电压偏差转换为频率偏移，通过轻量级模拟滤波器处理。谐波分量的RMS值作为紧凑特征，对工作点偏差具有单调敏感性，同时保持PVT角间的排序，确保在无精密参考或匹配比较器的情况下稳健运行。比率细化将温度和电源变化引起的校准后漂移抑制高达一个数量级。该特征可通过两个I/O引脚读取，实现无需ATE的现场测试。该电路占用6390 $\mu$m$^2$面积，功耗16.7 $\mu$W，与紧凑型ADC相比实现26倍面积缩减，与SAR实现相比实现近1500倍面积缩减。
英文摘要
Flexible electronics (FE) based on indium gallium zinc oxide (IGZO) unipolar thin-film transistor (TFT) technologies enable lightweight, conformable systems for wearable sensing, biomedical monitoring, and human-machine interfaces. These applications rely on analog and mixed-signal (AMS) blocks that must remain accurate despite key challenges: increased device variability from low-cost unipolar fabrication; susceptibility to post-manufacturing failures due to the absence of rigid packaging; parametric faults that degrade analog accuracy without hard digital failures; and the high cost and in-field inaccessibility of specialized Automatic Test Equipment (ATE) for disposable FE systems. Conventional test approaches relying on analog-to-digital converters (ADCs) incur prohibitive area overhead in resource-constrained systems; critically, ADC accuracy is itself subject to process, voltage, and temperature (PVT) variations, leading to test invalidations. This work proposes a frequency-domain test signature circuit exploiting spectral energy from a voltage-controlled oscillator (VCO) to detect faults and parametric deviations in AMS circuits under test. The VCO converts fault-induced control-voltage deviations into frequency shifts processed through lightweight analog filters. RMS values of harmonic components serve as compact signatures with monotonic sensitivity to operating-point deviations while preserving ordering across PVT corners, ensuring robust operation without precision references or matched comparators. A ratiometric refinement suppresses post-calibration drift from temperature and supply variation by up to an order of magnitude. The signature is readable via two I/O pins, enabling in-field test without ATE. The circuit occupies 6390 $μ$m$^2$ and consumes 16.7 $μ$W, achieving 26$\times$ area reduction versus compact ADCs and nearly 1500$\times$ versus SAR implementations.
