基于V-F变换的硅压阻压力传感器的处理电路

针对硅压阻压力传感器提出了一种基于电桥本身参数的温度自补偿方法，并设计了一种差分输入、双参数输出的高精度处理电路用以获得电桥参数。该电路用简单元件搭建差分输入的电荷平衡式V/F转换器，根据不同组态的频率输出解算电桥参数。该电路巧妙地利用差分输入方式消除了共模电压引起的误差，巧妙借用参考电阻消除了基准频率的影响，最终的输出频率只与被测量和参考电阻有关。经实验验证，电桥电阻的测量精度能达到0.0068%，经补偿后的压力传感器精度可达0.039%，相比补偿之前提高了一个数量级。

A Voltage-Frequency Conversion Based Signal Conditioning Circuit of Silicon Piezo-resistive Pressure Sensor

A temperature self-compensation method based on bridge parameters is proposed for silicon piezo-resis?tive pressure sensors in this paper. A high-precision processing circuit with differential input and dual parameters output is designed to measure bridge parameters. The circuit is a charge-balanced differential input V-F converter built by simple components. Bridge parameters are calculated by output frequency of different circuit configuration. The circuit eliminates the common mode voltage error and the reference frequency affect by differential input and reference resistance respectively. The final output frequency is related to the quantity to be measured and the refer?ence resistor. It is confirmed by experiment that the measured accuracy of the bridge resistors can reach 0.006 8%and the whole pressure sensors’precise is 0.039%after compensation,which demonstrates that this method can im?prove the measurement precision by one order of magnitude.