A 3-Axis Gyroscope for Electronic Stability Control With Continuous Self-Test

• Published in: IEEE journal of solid-state circuits 2016-01, Vol.51 (1), p.177-186
• Main Authors: Balachandran, Ganesh K., Petkov, Vladimir P., Mayer, Thomas, Balslink, Thorsten
• Format: Article
• Language: English
• Subjects: ASIL-D; Automotive components; Automotive electronics; Automotive engineering; Built-in self-test; Cancellation; electromechanical quadrature cancellation; electronic stability control (ESC); Electronics; force-feedback; gyroscope; Gyroscopes; MEMS; Monitoring; Noise; Quadratures; Safety; sensor resonant modes; Vehicles; Wheels
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2015.2496360

A three-axis automotive gyroscope ASIC for electronic stability control (ESC) with noise density that is less than 0.004°/s/√Hz in a 80 Hz bandwidth and an offset drift lower than ±0.1°/s over the automotive temperature range -40 to 140 °C, without any temperature compensation, is reported. A closed-loop, force-feedback architecture along with electromechanical quadrature cancellation enables the low noise and low offset-drift performance. The application of this work needs to meet the ASIL-D automotive safety standard which requires the highest level of automotive safety. Therefore, this work also presents a low-overhead approach for implementing accurate continuous safety monitoring to monitor defects, which can develop in the field, and can give rise to a false output. To achieve this, two test signals are injected into the quadrature cancellation loop to traverse the entire signal path. The system is clocked by a low-phase noise PLL, which allows the coexistence of the test signals and the measured signal in close proximity, without a noise penalty. The architecture of the drive loop is chosen to not only achieve low-phase noise but also robustness to parasitic mechanical modes of the sensor.