García-Romeo Daniel, Valero María R, Medrano Nicolás, Calvo Belén, Celma Santiago
Group of Electronic Design, Aragon Institute for Engineering Research, I3A, Facultad de Ciencias, Pedro Cerbuna 12, Zaragoza 50009, Spain.
Sensors (Basel). 2015 Sep 30;15(10):25260-76. doi: 10.3390/s151025260.
This paper proposes a battery-compatible electronic interface based on a general purpose lock-in amplifier (LIA) capable of recovering input signals up to the MHz range. The core is a novel ASIC fabricated in 1.8 V 0.18 µm CMOS technology, which contains a dual-phase analog lock-in amplifier consisting of carefully designed building blocks to allow configurability over a wide frequency range while maintaining low power consumption. It operates using square input signals. Hence, for battery-operated microcontrolled systems, where square reference and exciting signals can be generated by the embedded microcontroller, the system benefits from intrinsic advantages such as simplicity, versatility and reduction in power and size. Experimental results confirm the signal recovery capability with signal-to-noise power ratios down to -39 dB with relative errors below 0.07% up to 1 MHz. Furthermore, the system has been successfully tested measuring the response of a microcantilever-based resonant sensor, achieving similar results with better power-bandwidth trade-off compared to other LIAs based on commercial off-the-shelf (COTS) components and commercial LIA equipment.
本文提出了一种基于通用锁相放大器（LIA）的电池兼容电子接口，该接口能够恢复高达兆赫兹范围的输入信号。其核心是采用1.8 V 0.18 µm CMOS技术制造的新型专用集成电路（ASIC），它包含一个双相模拟锁相放大器，该放大器由精心设计的模块组成，可在宽频率范围内实现可配置性，同时保持低功耗。它使用方波输入信号进行操作。因此，对于电池供电的微控制系统，其中方波参考信号和激励信号可由嵌入式微控制器生成，该系统具有诸如简单性、通用性以及功耗和尺寸减小等固有优势。实验结果证实了该系统的信号恢复能力，在高达1 MHz的频率下，信噪比低至 -39 dB，相对误差低于0.07%。此外，该系统已成功测试了基于微悬臂梁的谐振传感器的响应，与其他基于商用现货（COTS）组件的锁相放大器和商用锁相放大器设备相比，在功率 - 带宽权衡方面取得了类似的结果且表现更优。
