A new current-mode wheatstone bridge based on a new fully differential operational transresistance amplifier

Abstract A new current-mode Wheatstone bridge (CMWB) using a new fully differential operational transresistance amplifier (FDOTRA) is presented in this paper. This proposed FDOTRA is an active element for the proposed CMWB and has the advantages of low input and output impedances, input voltage calibration, high transimpedance (Rm), large input range, and wide bandwidth. The proposed CMWB uses only one active component FDOTRA and four resistors without degrading CMWB performance. The proposed CMWB has a simple structure, high precision, wide range, small volume, and low cost. Therefore, the advantages of the proposed CMWB are twofold. Firstly, it reduces the number of sensing passive and active elements. Secondly, the proposed CMWB circuit offers a significant improvement in accuracy compared to other CMWB integrated circuit (IC). The proposed CMWB has been analyzed, simulated, and implemented. The proposed FDOTRA has been fabricated with TSMC 0.35 μm 2P4M CMOS processes. Its supply voltages are ±1.65 V. The open-loop gain and 3-dB bandwidth of the proposed FDOTRA are 69.2 dB and 16 MHz, respectively. The open-loop gain and 3-dB bandwidth of the FDOTRA based CMWB are 24.6 dB and 16 MHz, respectively. The experimental results show that the precision of the FDOTRA based CMWB is 92.4%.