| Popis: |
This article aims to present the computer-aided design, modeling, and simulation of a highly sensitive pressure transducer using a stress-sensitive complementary metal-oxide-semiconductor (CMOS) operational amplifier (op-amp) in differential amplifier configuration with varying input voltage and gain. The double diaphragm-based pressure sensing structure consists of a piezoresistance bridge that has been placed on the first diaphragm followed by an op-amp in differential amplifier configuration whose gain dependent input and feedback piezoresistors have been placed on the second diaphragm. Under externally applied pressure, piezoresistance-bridge will provide varying input voltage to the op-amp in differential amplifier configuration, whereas the input and feedback piezoresistors placed on the second diaphragm will provide varying dc gain. Finite element method based Intellisuite tool has been employed for the designing and simulation of the proposed pressure sensing structure. A two-stage operational amplifier circuit has been designed and implemented using $0.8~\mu \text{m}$ CMOS technology parameters in T-Spice simulator. From simulation results, the pressure sensitivity of the proposed pressure transducer shows a sensitivity of 15S.30 mV/MPa and 115S.13 mV/MPa for p-type and n-type sensing elements, respectively, which is significantly higher than traditional Wheatstone bridge based pressure sensor. This research work gives a novel idea of implementing stress-sensitive op-amp in differential amplifier configuration for the design and development of a highly sensitive pressure transducer. |
