基于模拟器件的微弱标准源的设计

Design of Weak Standard Source Based on Analog Devices

标准源要求电路的温漂低、信号的精度高。提出一种可编程微弱标准源,以MSP430为主控,完全16位DAC器件和精密调理电路为核心,辅以电源隔离、总线隔离和软件补偿等措施提高精度。对电路进行了温湿度适应性实验,能程控输出0~20 mV的微弱电压和4 mA^20 mA的电流,最大误差分别为±3μV和±2μA,在静电放电和电快速瞬变脉冲群抗扰度实验后,性能保持正常。电路为气象计量仪器的设计提供了参考。

Standard source requires low temperature drift of circuit and high precision of signal.A programmable weak precision source is proposed,which is controlled by MSP430,with 16-bit DAC device and precise conditioning circuit as the core,supplemented by power isolation,bus isolation and software compensation to improve the accuracy.Temperature and humidity adaptability experiments were carried out on the circuit.The programmable output voltage of 0~20 mV and current of 4 mA^20 mA were obtained.The maximum errors were±3μV and±2μA,respectively.The performance of the circuit remained normal after ESD and fast transient pulse group immunity experiments.The circuit provides a reference for the design of meteorological measuring instruments.