集成的模拟前端，MCU简化能量收集无线传感器节点的设计

　　集成的模拟前端，MCU简化能量收集无线传感器节点的设计

　　能源收集已经成为一种有效的方法来为监测环境因素的无线传感器节点供电。然而，对于传感器子系统本身，工程师在构建合适的解决方案时会面临重大挑战，增加了项目进度的延迟。许多传感器的设计，工程师可以利用低功耗的模拟前端（AFE）和专门的MCU IC制造商包括模拟设备，赛普拉斯半导体、芯片技术、德克萨斯文书，其中。

　　为了开发传感器系统，工程师们传统上依靠手工构建合适的信号链，结合运算放大器、比较器和相关组件来可靠地收集传感器数据。虽然从传感器获取信号的概念看似简单，工程师们发现自己面临一长串如传感器驱动和输出的要求，实际问题的采样率，信号路径校准，性能，和传感器诊断，在规定的功率预算。在信号路径本身中，与元件匹配、偏置微调、电路板布局和附近噪声源相关的挑战增加了建立有效模拟信号通路的进一步复杂问题。

　　Signal requirements

　　Because sensor outputs can be very small signals， sensor signal paths typically require low-noise programmable gain amplifiers （PGAs） with extremely-low offset voltage， as well as low temperature and offset drifts to reduce the chance of introducing errors. In many cases， the common-mode voltage output of the sensor is much larger than the signal of interest， so some designs may require amplifiers with sufficiently high common-mode rejection ratios.

　　Due to the small sensor signals and overall sensitivity to noise， sensor signal paths also typically include design elements designed to limit the noise floor. These designs typically incorporate filters to limit the signal bandwidth and reduce noise contributions. In addition， chopper-stabilized amplifiers might be used to reduce errors from 1/f noise of the amplifiers. Finally， the use of a ΣΔ ADC with its oversampling conversion method helps reduce noise and associated noise-filtering requirements.