The Fabrication Of Detection Circuit Based On Adaptive Filter For MEMS Acceleration Sensor

The MEMS acceleration sensor belongs to the Micro-Electro-Mechanical-System. It exists in the cross field of electronics and machinery. It greatly reduces the size of sensors and makes it simpler to sense, process and transfer the signals. As an important mechanical instrument, the MEMS acceleration sensor could be widely applied in many fields, such as civilian, military and medical device products. The detection circuit is a fatal auxiliary part of the sensor, and its performance always depends on the detection circuit. It is absolutely important to design a high-performance detection circuit because of its importance. And that is why we did the research of the detection of weak signal of the adaptive filter.This paper discussed and analyzed the organization and principle of capacitive acceleration sensor. Based on the actual desire, choose the acceleration sensor, design and test the circuit with considering the sensor, and compare the advantages and disadvantages of simulated testing circuit and digital testing circuit, then design the digital testing circuit based on adaptive algorithm, mainly discussed the acquire, preamplifier, A/D conversion, and other circuit of MEMS sensor’s small signal analog, as well as its technical performance advantages. According to the difference and advantages&disadvantages of several current popular algorithms for adaptive filter, analyze the algorithm. Based on the above, use matlab to simulate the algorithm, to do a deeply research of small signal testing performance of adaptive filter. After the theoretical study, based on FPGA hardware basis, using VHDL language to write algorithm, complete the micro acceleration sensor testing circuit under the adaptive algorithm with the combination of algorithm and hardware, and apply oscilloscope to directly measure the output wave of adaptive filter, and then get visual filter effect, at last, verify the testing purpose of this paper.