Precision readout circuits for capacitive microaccelerometers

2004-01-01
Yazdi, N
Külah, Haluk
Najafi, K
This paper presents a review of capacitive readout front-end circuits for high-precision accelerometers. The primary design parameters and the trade-offs affecting the resolution are presented. The discussions apply to all capacitive microsensor interfaces. Also a high-sensitivity capacitive accelerometer interface circuit for hybrid-integration with a surface/bulk micromachined micro-g accelerometer is described [7, 10]. The first generation of the circuit resolves 75aF of capacitance on similar to 120pF parasitic capacitance with a 200kHz sampling rate, and the second generation resolves 20aF with 1MHz sampling rate. The overall sensor-circuit module has a noise floor of 1.6 mu g/root HZ at ambient atmosphere.

Suggestions

A new design and a fabrication approach to realize a high performance three axes capacitive MEMS accelerometer
Aydemir, Akin; Terzioglu, Yunus; Akın, Tayfun (2016-06-15)
This paper presents a new fabrication approach and design for a three axis capacitive MEMS accelerometer that is capable of measuring externally applied accelerations in three orthogonal axes. Individual lateral and vertical axis accelerometers are fabricated in the same die on an SOI wafer which is anodically bonded to a glass substrate. Handle layer of the SOI wafer is used as the top electrode for the vertical axis accelerometer. This accelerometer has a 2 mm(2) perforated electrode area anchored to the ...
Noise analysis and characterization of a sigma-delta/capacitive microaccelerometer
Külah, Haluk; Yazdi, N; Najafi, K (2006-02-01)
This paper reports a high-sensitivity low-noise capacitive accelerometer system with one micro-g/root Hz resolution. The accelerometer and interface electronics together operate as a second-order electromechanical sigma-delta modulator. A detailed noise analysis of electromechanical sigma-delta capacitive accelerometers with a final goal of achieving sub-jig resolution is also presented. The analysis and test results have shown that amplifier thermal and sensor charging reference voltage noises are dominant...
Fabrication of a Three-Axis Capacitive MEMS Accelerometer on a Single Substrate
Aydemir, Akin; Akın, Tayfun (2015-11-04)
This paper presents a new fabrication approach and a design for the fabrication of a three-axis capacitive MEMS accelerometer where differential sensing is enabled for all sense directions. In this approach, individual lateral and vertical axis accelerometers are fabricated in the same die on an SOI wafer which is eutectically bonded to a glass substrate. Differential sensing for the vertical axis accelerometer is realized by defining the proof mass of the accelerometer on the structural layer of the SOI wa...
A Capacitive MEMS Accelerometer Readout with Concurrent Detection and Feedback Using Discrete Components
Terzioglu, Yunus; Alper, Said Emre; Azgın, Kıvanç; Akın, Tayfun (2014-05-08)
This paper presents an analog readout method for capacitive MEMS accelerometers in which the feedback actuation and capacitive detection are achieved simultaneously on the same electrode set. The presented circuit operates in closed-loop for improved linearity, and it is constructed in a hybrid platform package in which off-the-shelf discrete components are used together with the silicon-on-glass micro-accelerometer. The system is developed as a practical solution to reduce the complexity of the readout cir...
Process Development for the Fabrication of a Three Axes Capacitive MEMS Accelerometer
Aydemir, Akin; Akın, Tayfun (2015-09-09)
This paper presents a new approach for the fabrication of a three-axis capacitive MEMS accelerometer that is capable of differentially sensing the acceleration in all three orthogonal axes. For the first time in literature, differential sensing for the out of plane direction is achieved by defining a movable sensing electrode on the structural layer of the SOI wafer that is sandwiched between two stationary electrodes defined on the glass substrate and the handle layer of the SOI wafer enabling the differen...
Citation Formats
N. Yazdi, H. Külah, and K. Najafi, “Precision readout circuits for capacitive microaccelerometers,” 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46772.