摘要：Accelerometers have a wide range application in many fields, such as airbag deployment system and electronic stability control system in vehicles, and inertial navigation system in aircrafts and rockets. As Micro-Electro-Mechanical System (MEMS) technology advances, accelerometers are made smaller and smaller, often integrated in a single chip, with lower implementation costs and power consumptions. Modern MEMS accelerometers can be used in portable devices such as cell phones, RFID tags and even integrated in other sensors. This paper presents chip-level design and implementation of a second order sigma-delta interface circuit used in capacitive micro-accelerometers. The interface circuit provides 1-bit data stream and operates at a sampling frequency of 2.5MHz. The system model considers non-ideal factors in the circuit such as nonlinear distortion and noises. These non-ideal factors have been discussed through system level simulation in MATLAB. The micro-accelerometer, which is a highly integrated MEMS device, is then designed and implemented in silicon-on-insulator (SOI) substrate. Finally, the chip-level layout of interface circuit is implemented. Results have shown the chip with area of 1.32mm2 and power consumption of about 5mW.
