High-Performance Dual-Axis Gyroscope ASIC Design
This chapter presents a high-performance dual-axis (pitch and roll) MEMS vibratory gyroscope readout ASIC which converts angular rate information to digital output. Two signal-processing chains surrounding the MEMS sensor are implemented, namely the drive channel and the sense channel. The drive channel drives the sensor to resonate at its resonant frequency, which produces a velocity of the sensor disc to generate the Coriolis force during angular rotation. The sense channel employs a low noise transimpedance amplifier (TIA) followed by a demodulator (DM), which down converts the angular rate input signal from the resonant frequency to baseband. Two switched-capacitor (SC) 2–1 MASH delta-sigma ADCs convert the input angular rate from the pitch and roll arises to digital output. The reference of the ADC is also demodulated from the sensor output to cancel out supply voltage dependence. The whole ASIC, including the high-voltage MEMS sensor driver, digital filter, on-chip regulator, and temperature sensor, is fabricated in a 0.18 μm CMOS technology with an area of 7.3 mm2. The design achieves a noise floor of 0.0032°/s/√Hz and 0.0061°/s/√Hz in full-scale input ranges of 500°/s and 2000°/s, respectively, over a 480 Hz signal bandwidth. The bias instability is measured as 2.5°/h at input range of 500°/s. The whole ASIC consumes 7 mA from a 3 V supply.
The authors would like to thank their colleagues from the High-Performance Inertial sensor group at Analog Devices Inc. (both in Wilmington and Greensboro) for their help during design, layout, and chip evaluations.
- 1.Marek J. MEMS for automotive and consumer electronics. In: IEEE International Solid-State Circuits Conference (ISSCC) Digest of Technical Papers, San Francisco, 2010.Google Scholar
- 3.Clark WA. Micromachined vibratory rate gyroscopes, Dissertation, 1997.Google Scholar
- 4.Balachandran GK, Petkov VP, Mayer T, Blalslink T. A 3-axis gyroscope for electronic stability control with continuous self-test. IEEE J Solid State Circuits. 2016;50(1):177–86.Google Scholar
- 8.Meijer G. Smart sensor systems. Wiley; 2008.Google Scholar
- 9.Meijer G, Makinwa K, Pertijs M. Smart sensor systems: emerging technologies and applications. Wiley; 2014.Google Scholar
- 11.Ezekwe C, Geiger W, Ohms T. A 3-axis open-loop gyroscope with demodulation phase error correction. In: Proceedings of IEEE international solid-state circuits conference, San Francisco, 2015.Google Scholar
- 12.Prandi L, et al. A low-power 3-axis digital-output MEMS gyroscope with single drive and multiplexed angular rate readout. In: Solid-State Circuits Conference Digest of Technical Papers (ISSCC), San Francisco, 2011.Google Scholar
- 17.Tan Z, Nguyen K, Yan J, Samuels H, Keating S, Crocker P, Clark B. A dual-axis MEMS vibratory gyroscope ASIC with 0.0061°/s/VHz noise floor over 480 Hz bandwidth. In: 2017 IEEE Asian Solid-State Circuits Conference (A-SSCC), Seoul, 2017.Google Scholar
- 21.Schreier R, Temes GC. Understanding delta-sigma data converters. Wiley-IEEE Press; 2004.Google Scholar