A SOI-based Low-noise Low Gain Error Readout Circuit for Resistive MEMS Sensor Applications

To address the performance stability issues of MEMS sensor readout circuits in wide temperature range environments, this paper presents the design of a readout circuit, featuring high gain stability and low noise characteristics, based on $0.15 \mu \mathrm{~m}$ Silicon-On-Insulator (SOI) technology. The circuit performance is evaluated through system-level testing at three temperatures: $-40^{\circ} \mathrm{C}, 27^{\circ} \mathrm{C}$, and $125^{\circ} \mathrm{C}$. The gain error is less than $1 \%$ across all conditions. Chopper stabilization technique is implemented to reduce the low-frequency noise of the proposed readout circuit. Simulation result shows that the proposed circuit exhibits $52 \mathrm{nV} / \sqrt{H z}$ at 1 Hz frequency, demonstrating noise resilience.