Most of the resistive sensors have a large baseline resistor and a relatively small incremental change in the resistor value due to the measurand. A half-bridge-based versatile $\Delta R/R_{s}$ measurement system for a wide range of resistive sensors is reported in this article. A four-phase auto-calibration-based differential and ratiometric operation is used to compensate for the baseline resistance of the sensor and the mismatches due to the non-ideal circuit parameters. A low-noise application-specific current generator and low noise, high CMRR current-mode instrumentation amplifier is designed and fabricated in UMC 180-nm technology. A prototype board of the $\Delta R/R_{s}$ measurement system is developed and tested. The experimental results show that the proposed system is able to detect even smaller ppm level of about 72 ppm of $\Delta R/R_{s}$ for the base resistor $R_{s}$ value as high as 0.5 $\text{M}\Omega $ with a relative error of less than ±1%. The effect of the parasitic capacitors on the sensor response is also tested experimentally. Finally, the proposed system is tested with an in-house fabricated displacement sensor.

中文翻译：

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具有低噪声仪表 ASIC 的自动校准电阻测量系统

大多数电阻式传感器都有一个大的基线电阻和由于被测量而引起的电阻值的相对较小的增量变化。基于半桥的多功能 $\Delta R/R_{s}$ 本文报道了用于各种电阻传感器的测量系统。基于四相自动校准的差分和比率操作用于补偿传感器的基线电阻和由于非理想电路参数引起的不匹配。低噪声专用电流发生器和低噪声、高 CMRR 电流模式仪表放大器采用 UMC 180-nm 技术设计和制造。一个原型板 $\Delta R/R_{s}$ 开发和测试测量系统。实验结果表明，所提出的系统能够检测到更小的 ppm 水平，约为 72 ppm $\Delta R/R_{s}$ 对于基极电阻 $R_{s}$ 值高达 0.5 $\text{M}\Omega $ 相对误差小于±1%。还通过实验测试了寄生电容对传感器响应的影响。最后，所提出的系统使用内部制造的位移传感器进行测试。