一种基于AD7795模数转换器的低功耗PT100温度采集系统设计

Design of a low power consumption PT100 temperature acquisition system based on AD7795 A/D converter

为了提高工业应用中PT100温度采集精度和降低功耗,开发了一款以内部定时器来实现温度信号的定时采集,利用NB-IoT通信模块进行无线传输的温度采集系统。该系统在每次转换数据之前都需先对其实施复位,并保持500μs后再对AD7795进行初始化。通过每次数据采集与存储完成后便转为休眠状态的方式实现低功耗设计。选择测试温度范围是-50～150℃测试发现,每次温度数据采集曲线均具有良好的重合度,系统可以实现良好的稳定性。与实际测量温度的绝对误差最大值是0. 034℃,完全满足系统的温度精度要求。

In order to improve the accuracy of PT100 temperature acquisition and reduce power consumption in industrial applications,a temperature acquisition system with a partial timer is developed to realize the timing acquisition of temperature signals.The system needs to reset the data before converting it every time,and keep it 500 francs before initializing AD7795.The design of low power consumption is realized by changing to sleep state after data collection and storage.Choose the test temperature range is-50~150℃test found that every time the temperature data acquisition curve has a good coincidence degree,the system can achieve good stability.With the actual measured the absolute error of temperature is 0.034℃,fully meet the requirements of the temperature precision of this system.