Low-Voltage Current-Sensing CMOS Interface Circuit for Piezo-Resistive Pressure Sensor

ETRI Journal

关键词: piezo-resistive sensor;    Wheatstone bridge;    interface circuit current sensing;    resistive readout;    current amplifier;    CMOS amplifier;   

Others  :  1185600
DOI  :  10.4218/etrij.07.0106.0035

【 摘 要 】

A new low-voltage CMOS interface circuit with digital output for piezo-resistive transducer is proposed. An input current sensing configuration is used to detect change in piezo-resistance due to applied pressure and to allow low-voltage circuit operation. A simple 1-bit first-order delta-sigma modulator is used to produce an output digital bitstream. The proposed interface circuit is realized in a 0.35 µm CMOS technology and draws less than 200 A from a single 1.5 V power supply voltage. Simulation results show that the circuit can achieve an equivalent output resolution of 9.67 bits with less than 0.23% non-linearity error.

   

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