Research on Temperature Hysteresis Error Suppression Technology for Capacitive MEMS Accelerometers

The performance of MEMS accelerometers is highly sensitive to temperature variations, manifesting as zero drift, sensitivity drift, and hysteresis error. This paper presents a low-temperature-drift, low-noise interface ASIC for capacitive MEMS accelerometers. The circuit employs an analog closed-loop architecture comprising a small-capacitance front-end detection circuit, a variable gain amplifier (VGA), a correlated double sampling (CDS) circuit, a PID controller, and a feedback module. To suppress temperature-induced errors, key optimizations are implemented: the charge amplifier employs active and passive charge compensation techniques to reduce common-mode offset drift; the VGA uses switched feedback resistors for gain adjustment; a Class-AB unity-gain buffer enhances driving capability while isolating load interference; and a high-order compensated bandgap reference with pre-regulation achieves low temperature drift and high power supply rejection. Post-layout simulations demonstrate a system sensitivity of approximately 2.27 V/g, a sensitivity temperature coefficient of 74.55 ppm/°C, and a 1σ zero-bias temperature drift of 1.757 mg. Experimental results over the full temperature range from -45°C to 85°C show an output hysteresis error of only 0.6 mg. These results validate the effectiveness of the proposed temperature hysteresis error suppression technique, providing a valuable reference for the design of high-precision MEMS accelerometer interface circuits.