基于异或运算相敏整流的数字磁通门设计

针对模拟电路磁通门温度特性差,数字电路磁通门占用接口多且反应慢的难题,提出了一种基于异或运算相敏整流电路的数字式闭环磁通门传感器.该异或运算电路是将高速AD采样得到的二次谐波信号与参考方波信号进行异或逻辑运算后经高速DA完成了数字相敏整流功能.采用基于异或运算相敏整流电路的磁通门系统既改善了温度特性,同时也节约了数字接口,减少了数字处理器的运算负担.通过实验测试,结果显示:系统测量范围为±62900 nT,线性度为2.8×10-4,分辨力约为2 nT,磁通门反馈回路的-3 dB带宽约为240 Hz.

Design of Digital Fluxgate Sensor Based on Phase-sensitive of XOR Operation

In order to solve the poor temperature characteristic of the fluxgate based on analog circuit and the prob-lem that the fluxgate of digital circuit has many interfaces and slow response. A digital closed loop fluxgate sensor based on phase-sensitive circuit of XOR operation has been proposed. The phase-sensitive circuit of XOR operation has completed the function of the digital phase-sensitive through which digital signal sampled the two harmonics by the high-speed AD and the square wave signals has been processed through the XOR gate, and then transmitted them directly to the high-speed DA. The fluxgate system of phase-sensitive circuit based on XOR operation not only improves the temperature characteristics,but also saves the digital interface and reduces the computational burden of the digital processor. Experiments show that the measurement range of the system is 62900 nT,the linearity is 2.8× 10-4 ,the resolution is about 2 nT,and the -3 dB bandwidth of the fluxgate feedback loop is about 240 Hz.