A CMOS Readout Circuit for SOI Resonant Accelerometer With 4-$\mu \rm g$ Bias Stability and 20-$ \mu\rm g/\sqrt{{\hbox{Hz}}}$ Resolution

A fully differential CMOS readout circuit for SOI resonant accelerometer is reported. The readout circuit is essentially an oscillator, consisting of an oscillator and a low noise automatic amplitude control (AAC) loop. A differential sense resonator is proposed to facilitate fully differential circuit topology and improves the SNR under a 3.3-V supply. A second-order AAC loop filter and a novel chopper stabilized rectifier are employed in the AAC loop to remove the noises, in particular, the 1/f noise, and to minimize the phase noise caused by the amplitude stiffening effect. The strong driving feedthrough is avoided by separating the drive and sense operation in the time domain, while using the same electrodes. The complete resonant accelerometer operates under a 3.3-V supply and achieves 140-Hz/g scaling factor, 20 mug/radicHz resolution and 4 mug bias stability. The readout circuit draws 7 mA under 3.3-V supply.

[1]  F. Gardner,et al.  Charge-Pump Phase-Lock Loops , 1980, IEEE Trans. Commun..

[2]  Jeffrey T. Borenstein,et al.  The Silicon Oscillating Accelerometer: A MEMS Inertial Instrument for Strategic Missile Guidance , 1998 .

[3]  B. L. Norling.  Precision gravity measurement utilizing Accelerex vibrating beam accelerometer technology , 1990, IEEE Symposium on Position Location and Navigation. A Decade of Excellence in the Navigation Sciences.

[4]  Gang Zhang,et al.  A post-CMOS micromachined lateral accelerometer , 2002 .

[5]  Farrokh Ayazi,et al.  Micromachined inertial sensors , 1998, Proc. IEEE.

[6]  M. Helsel,et al.  A navigation grade micro-machined silicon accelerometer , 1994, Proceedings of 1994 IEEE Position, Location and Navigation Symposium - PLANS'94.

[7]  L. Edmonds,et al.  Radiation response of a MEMS accelerometer: an electrostatic force , 1998 .

[8]  C. Toumazou,et al.  Feedforward compensation techniques in the design of low voltage opamps and OTAs , 1998, ISCAS '98. Proceedings of the 1998 IEEE International Symposium on Circuits and Systems (Cat. No.98CH36187).

[9]  C.T.-C. Nguyen,et al.  Series-resonant VHF micromechanical resonator reference oscillators , 2004, IEEE Journal of Solid-State Circuits.

[10]  K. Najafi,et al.  A monolithic three-axis micro-g micromachined silicon capacitive accelerometer , 2005, Journal of Microelectromechanical Systems.

[11]  Larry D. Edmonds,et al.  Electric currents through ion tracks in silicon devices , 1998 .

[12]  T. A. Roessig,et al.  Nonlinear mixing in surface-micromachined tuning fork oscillators , 1997, Proceedings of International Frequency Control Symposium.

[13]  강수진.  Charge-Pump Phase-Locked Loops에 관한 연구 및 회로 설계 , 1996 .

[14]  S. Sherman,et al.  Single-chip surface micromachined integrated gyroscope with 50°/h Allan deviation , 2002, IEEE J. Solid State Circuits.

[15]  Gabor C. Temes,et al.  Circuit techniques for reducing the effects of op-amp imperfections: autozeroing, correlated double sampling, and chopper stabilization , 1996, Proc. IEEE.

[16]  Christopher C. T. Nguyen,et al.  Influence of automatic level control on micromechanical resonator oscillator phase noise , 2003, IEEE International Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum, 2003. Proceedings of the 2003.

[17]  T. A. Roessig,et al.  Surface-micromachined resonant accelerometer , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[18]  T. Serrano-Gotarredona,et al.  A loss control feedback loop for VCO stable amplitude tuning of RF integrated filters , 2002, 2002 IEEE International Symposium on Circuits and Systems. Proceedings (Cat. No.02CH37353).

[19]  W. Burns,et al.  RESONANT MICROBEAM ACCELEROMETERS , 1995 .

[20]  D. Leeson.  A simple model of feedback oscillator noise spectrum , 1966 .

[21]  Bernhard E. Boser,et al.  A three-axis micromachined accelerometer with a CMOS position-sense interface and digital offset-trim electronics , 1999, IEEE J. Solid State Circuits.

[22]  W. C. Albert.  Monolithic quartz structure vibrating beam accelerometer (VBA) , 1994, Proceedings of IEEE 48th Annual Symposium on Frequency Control.

[23]  Kukjin Chun,et al.  An inertial-grade laterally-driven MEMS differential resonant accelerometer , 2004, Proceedings of IEEE Sensors, 2004..

[24]  Eric A. M. Klumperink,et al.  Low-Frequency Noise Phenomena in Switched MOSFETs , 2007, IEEE Journal of Solid-State Circuits.

[25]  G. Fedder,et al.  CMOS MEMS oscillator for gas chemical detection , 2004, Proceedings of IEEE Sensors, 2004..

[26]  D. W. Allan,et al.  Time and Frequency (Time-Domain) Characterization, Estimation, and Prediction of Precision Clocks and Oscillators , 1987, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[27]  B. Boser,et al.  A monolithic surface micromachined Z-axis gyroscope with digital output , 2000, 2000 Symposium on VLSI Circuits. Digest of Technical Papers (Cat. No.00CH37103).

[28]  B. Boser,et al.  A monolithic surface micromachined accelerometer with digital output , 1995 .