公开(公告)号：EP4269949A2

公开(公告)日：2023-11-01

申请号：EP23162780.3

申请日：2023-03-20

Applicant: STMicroelectronics Inc. ,  STMicroelectronics S.r.l.

Inventor： HU, Yamu ,  SAHOO, Naren K ,  NALLAMOTHU, Pavan ,  FANG, Deyou ,  MCCLURE, David ,  GARBARINO, Marco

IPC: G01C25/00

Abstract: At start-up of a microelectromechanical system (MEMS) gyroscope, the drive signal is inhibited, and the phase, frequency and amplitude of any residual mechanical oscillation is sensed and processed to determine a process path for start-up. In the event that the sensed frequency of the residual mechanical oscillation is a spurious mode frequency and a quality factor of the residual mechanical oscillation is sufficient, an anti-phase signal is applied as the MEMS gyroscope drive signal in order to implement an active dampening of the residual mechanical oscillation. A kicking phase can then be performed to initiate oscillation. Also, in the event that the sensed frequency of the residual mechanical oscillation is a resonant mode frequency with sufficient drive energy, a quadrature phase signal with phase lock loop frequency control and amplitude controlled by the drive energy is applied as the MEMS gyroscope drive signal in order to induce controlled oscillation.

公开(公告)号：EP4269949A3

公开(公告)日：2024-04-10

申请号：EP23162780.3

申请日：2023-03-20

Applicant: STMicroelectronics Inc. ,  STMicroelectronics S.r.l.

Inventor： HU, Yamu ,  SAHOO, Naren K ,  NALLAMOTHU, Pavan ,  FANG, Deyou ,  MCCLURE, David ,  GARBARINO, Marco

IPC: G01C25/00

Abstract: At start-up of a microelectromechanical system (MEMS) gyroscope, the drive signal is inhibited, and the phase, frequency and amplitude of any residual mechanical oscillation is sensed and processed to determine a process path for start-up. In the event that the sensed frequency of the residual mechanical oscillation is a spurious mode frequency and a quality factor of the residual mechanical oscillation is sufficient, an anti-phase signal is applied as the MEMS gyroscope drive signal in order to implement an active dampening of the residual mechanical oscillation. A kicking phase can then be performed to initiate oscillation. Also, in the event that the sensed frequency of the residual mechanical oscillation is a resonant mode frequency with sufficient drive energy, a quadrature phase signal with phase lock loop frequency control and amplitude controlled by the drive energy is applied as the MEMS gyroscope drive signal in order to induce controlled oscillation.

公开(公告)号：EP4170356A1

公开(公告)日：2023-04-26

申请号：EP22200494.7

申请日：2022-10-10

Applicant: STMicroelectronics S.r.l. ,  STMicroelectronics Inc.

Inventor： GARBARINO, Marco ,  CHOI, Davy ,  RIZZINI, Francesco ,  HU, Yamu

IPC: G01P21/00 ,  G01P15/125 ,  G01P15/18 ,  G01P15/08

Abstract: A microelectromechanical system (MEMS) accelerometer sensor (12x, 12y, 12z) has a mobile mass and a sensing capacitor. To self-test the sensor, a test signal having a variably controlled excitation voltage and a fixed pulse width is applied to the sensing capacitor. The leading and trailing edges of the test signal are aligned to coincide with reset phases of a sensing circuit (32-36) coupled to the sensing capacitor. The variably controlled excitation voltage of the test signal is configured to cause an electrostatic force which produces a desired physical displacement of the mobile mass. During a read phase of the sensing circuit, a variation in capacitance of sensing capacitor due to the actual physical displacement of the mobile mass is sensed for comparison to the desired physical displacement.