Ultra-low-noise TIA topology for MEMS gyroscope readout

This paper proposes a TIA topology that can be used in accelerometer and gyroscope systems. The proposed TIA topology considerably relaxes the trade-off among the transimpedance gain, bandwidth, and input referred current noise without increasing the power consumption. Furthermore, this paper presents a model for gyroscope microelectromechanical systems (MEMS) resonator that enables us, unlike prior works, to predict the resolution of the gyroscope system at the early stage of the design. In this model, the noise arising from driving loop blocks is compared with the noise of sense channel blocks. It has been illuminated that the noise of sense transimpedance amplifier (TIA) is the most influential in the resolution of the gyroscope system. To improve the resolution, the proposed TIA is employed in the sense channel of the gyroscope system. It enhances the resolution by about 57% compared with the conventional TIA employed in the sense channel. Measurement results of a discrete-element prototype also verify the performance improvement of the proposed TIA topology.