Integrated chip of capacitive three-axis accelerometer and sensing circuit

A CMOS-microelectromechanical system 0.18 μm process of the Taiwan Semiconductor Manufacturing Company is used to design an integrated chip of a capacitive three-axis accelerometer and a sensing circuit. The sensing architecture uses capacitive sensing principles, and the three axes are integrated on the same structure and share the same mass. The three-axis design method can not only reduce the chip area but also has good sensing ability. The readout circuit architecture combines two capacitor voltage converters and a subtraction amplifier, which can change the sensing signal into voltage amplitude values. As a result, the total chip area is 1.6 × 2.0 mm², and the sensing range is from 1 to 4 G. The simulated sensitivities of X, Y, and Z are 34.8, 20.0, and 13.7 mV/G, respectively.