Patents by Inventor Derek Shaeffer
Derek Shaeffer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 10247555Abstract: A round-robin sensing device is disclosed. The round-robin sensing device comprises a MEMS device, wherein the MEMS device includes first and second sense electrodes. The round-robin sensing device also comprises a multiplexer coupled to the first and second sense electrodes, at least one sense amplifier coupled to the multiplexer, a demodulator coupled to the at least one sense amplifier, and an integrate and dump circuit coupled to the demodulator. Finally, the round-robin sensing device comprises an analog-to-digital converter (ADC) coupled to the de-multiplexer, wherein the multiplexer, the at least one sense amplifier and the demodulator provide a continuous time sense path during amplification that is resettable and wherein the integrate and dump circuit and the ADC provide a discrete time processing path.Type: GrantFiled: July 21, 2016Date of Patent: April 2, 2019Assignee: InvenSense, Inc.Inventors: Derek Shaeffer, Stanley Wang
-
Patent number: 10228249Abstract: A gyroscope system comprises a MEMS gyroscope coupled to a drive system and a sense system. The drive system maintains the MEMS gyroscope in a state of oscillation and the sense system for receiving, amplifying, and demodulating an output signal of the MEMS gyroscope that is indicative of the rate of rotation. The gyroscope system further includes a phase-locked look (PLL) which receives a reference clock (REFCLK) from the drive system and produces a system clock (CLK). Finally, the gyroscope system includes a controller operating on the system clock sets an operating state of the drive system and the sense system and also controls a state of the PLL. One or more system state variables are maintained in a substantially fixed state during a protect mode thereby enabling rapid transitions between a low-power mode and a normal operating mode of the gyroscope system.Type: GrantFiled: September 30, 2016Date of Patent: March 12, 2019Assignee: InvenSense, Inc.Inventors: Derek Shaeffer, Stanley Wang
-
Patent number: 10001387Abstract: A MEMS capacitive sensing interface includes a sense capacitor having a first terminal and a second terminal, and having associated therewith a first electrostatic force. Further included in the MEMS capacitive sensing interface is a feedback capacitor having a third terminal and a fourth terminal, the feedback capacitor having associated therewith a second electrostatic force. The second and the fourth terminals are coupled to a common mass, and a net electrostatic force includes the first and second electrostatic forces acting on the common mass. Further, a capacitance measurement circuit measures the sense capacitance and couples the first terminal and the third terminal. The capacitance measurement circuit, the sense capacitor, and the feedback capacitor define a feedback loop that substantially eliminates dependence of the net electrostatic force on a position of the common mass.Type: GrantFiled: March 1, 2016Date of Patent: June 19, 2018Assignee: Invensense, Inc.Inventors: Baris Cagdaser, Derek Shaeffer, Joseph Seeger
-
Patent number: 9880063Abstract: A pressure sensor is provided which produces a measurement of the displacement and a measurement of a natural frequency of the diaphragm which are then combined to produce a compensated measurement of the displacement of the diaphragm, thereby substantially eliminating the dependence of the compensated displacement measurement on strain.Type: GrantFiled: March 3, 2014Date of Patent: January 30, 2018Assignee: INVENSENSE, INC.Inventors: Derek Shaeffer, Stanley Wang
-
Publication number: 20170016723Abstract: A gyroscope system comprises a MEMS gyroscope coupled to a drive system and a sense system. The drive system maintains the MEMS gyroscope in a state of oscillation and the sense system for receiving, amplifying, and demodulating an output signal of the MEMS gyroscope that is indicative of the rate of rotation. The gyroscope system further includes a phase-locked look (PLL) which receives a reference clock (REFCLK) from the drive system and produces a system clock (CLK). Finally, the gyroscope system includes a controller operating on the system clock sets an operating state of the drive system and the sense system and also controls a state of the PLL. One or more system state variables are maintained in a substantially fixed state during a protect mode thereby enabling rapid transitions between a low-power mode and a normal operating mode of the gyroscope system.Type: ApplicationFiled: September 30, 2016Publication date: January 19, 2017Inventors: Derek SHAEFFER, Stanley WANG
-
Patent number: 9506757Abstract: A gyroscope system comprises a MEMS gyroscope coupled to a drive system and a sense system. The drive system maintains the MEMS gyroscope in a state of oscillation and the sense system for receiving, amplifying, and demodulating an output signal of the MEMS gyroscope that is indicative of the rate of rotation. The gyroscope system further includes a phase-locked look (PLL) which receives a reference clock (REFCLK) from the drive system and produces a system clock (CLK). Finally, the gyroscope system includes a controller operating on the system clock sets an operating state of the drive system and the sense system and also controls a state of the PLL. One or more system state variables are maintained in a substantially fixed state during a protect mode thereby enabling rapid transitions between a low-power mode and a normal operating mode of the gyroscope system.Type: GrantFiled: November 22, 2013Date of Patent: November 29, 2016Assignee: INVENSENSE, INC.Inventors: Derek Shaeffer, Stanley Wang
-
Publication number: 20160327393Abstract: A round-robin sensing device is disclosed. The round-robin sensing device comprises a MEMS device, wherein the MEMS device includes first and second sense electrodes. The round-robin sensing device also comprises a multiplexer coupled to the first and second sense electrodes, at least one sense amplifier coupled to the multiplexer, a demodulator coupled to the at least one sense amplifier, and an integrate and dump circuit coupled to the demodulator. Finally, the round-robin sensing device comprises an analog-to-digital converter (ADC) coupled to the de-multiplexer, wherein the multiplexer, the at least one sense amplifier and the demodulator provide a continuous time sense path during amplification that is resettable and wherein the integrate and dump circuit and the ADC provide a discrete time processing path.Type: ApplicationFiled: July 21, 2016Publication date: November 10, 2016Inventors: Derek SHAEFFER, Stanley WANG
-
Patent number: 9459274Abstract: A round-robin sensing device is disclosed. The round-robin sensing device comprises a MEMS device, wherein the MEMS device includes first and second sense electrodes. The round-robin sensing device also comprises a multiplexer coupled to the first and second sense electrodes, at least one sense amplifier coupled to the multiplexer, a demodulator coupled to the at least one sense amplifier, and an integrate and dump circuit coupled to the demodulator. Finally, the round-robin sensing device comprises an analog-to-digital converter (ADC) coupled to the de-multiplexer, wherein the multiplexer, the at least one sense amplifier and the demodulator provide a continuous time sense path during amplification that is resettable and wherein the integrate and dump circuit and the ADC provide a discrete time processing path.Type: GrantFiled: August 2, 2013Date of Patent: October 4, 2016Assignee: INVENSENSE, INC.Inventors: Derek Shaeffer, Stanley Wang
-
Publication number: 20160178393Abstract: A MEMS capacitive sensing interface includes a sense capacitor having a first terminal and a second terminal, and having associated therewith a first electrostatic force. Further included in the MEMS capacitive sensing interface is a feedback capacitor having a third terminal and a fourth terminal, the feedback capacitor having associated therewith a second electrostatic force. The second and the fourth terminals are coupled to a common mass, and a net electrostatic force includes the first and second electrostatic forces acting on the common mass. Further, a capacitance measurement circuit measures the sense capacitance and couples the first terminal and the third terminal. The capacitance measurement circuit, the sense capacitor, and the feedback capacitor define a feedback loop that substantially eliminates dependence of the net electrostatic force on a position of the common mass.Type: ApplicationFiled: March 1, 2016Publication date: June 23, 2016Inventors: Baris Cagdaser, Derek Shaeffer, Joseph Seeger
-
Publication number: 20160134237Abstract: In a first aspect, an oscillator is disclosed. The oscillator comprises a digital circuit; and at least one Microelectromechanical system (MEMS) resonator. The oscillator includes a non-volatile memory, the non-volatile memory (NVM) storing a frequency value related to a resonant frequency of the at least one MEMS resonator. The digital circuit utilizes the frequency value stored in the NVM to provide a measure of real time from the MEMS resonator. In a second aspect, a system is disclosed. The system includes a processor and at least one Microelectromechanical system (MEMS) resonator operating at first frequency. The system also includes a memory. The memory storing a frequency value related to a resonant frequency of the at least one MEMS resonator. The frequency value is measured by an outside source. The processor utilizes the frequency value stored in the memory to provide a measure of real time from the MEMS resonator.Type: ApplicationFiled: November 11, 2014Publication date: May 12, 2016Inventors: Stephen LLOYD, Derek SHAEFFER
-
Patent number: 9304155Abstract: A MEMS capacitive sensing interface includes a sense capacitor having a first terminal and a second terminal, and having associated therewith a first electrostatic force. Further included in the MEMS capacitive sensing interface is a feedback capacitor having a third terminal and a fourth terminal, the feedback capacitor having associated therewith a second electrostatic force. The second and the fourth terminals are coupled to a common mass, and a net electrostatic force includes the first and second electrostatic forces acting on the common mass. Further, a capacitance measurement circuit measures the sense capacitance and couples the first terminal and the third terminal. The capacitance measurement circuit, the sense capacitor, and the feedback capacitor define a feedback loop that substantially eliminates dependence of the net electrostatic force on a position of the common mass.Type: GrantFiled: December 19, 2012Date of Patent: April 5, 2016Assignee: INVENSENSE, INC.Inventors: Baris Cagdaser, Derek Shaeffer, Joseph Seeger
-
Patent number: 9285207Abstract: A method and system for measuring displacement of a structure is disclosed. The method and system comprise providing a first capacitance and providing a second capacitance. The first and second capacitances share a common terminal. The method and system further include determining a difference of the inverses of the value of the first and second capacitances when the structure is displaced. The first capacitance varies in inverse relation to the displacement of the structure.Type: GrantFiled: July 26, 2013Date of Patent: March 15, 2016Assignee: INVENSENSE, INC.Inventors: Baris Cagdaser, Du Chen, Hasan Akyol, Derek Shaeffer
-
Patent number: 9124310Abstract: Systems and methods are provided for a broadband, closed-loop RF transmitter for multi-band applications that employs a single RF path to service multiple bands of operation. Embodiments of the present disclosure implement a broadband impedance matching module, which avoids the need for several costly and complex narrow-band matching networks. In an embodiment, the broadband impedance matching module includes concentric, mutually-coupled inductors. By adding this broadband impedance matching functionality, delay is significantly reduced because a single path can be used to service multiple bands.Type: GrantFiled: January 27, 2014Date of Patent: September 1, 2015Assignee: Broadcom CorporationInventors: Mohamed A. Mostafa, Derek Shaeffer
-
Patent number: 9098098Abstract: A curvature-corrected bandgap reference is disclosed. The curvature-corrected bandgap reference comprises a Brokaw bandgap circuit. The Brokaw bandgap circuit includes an output node providing a reference voltage. The Brokaw bandgap circuit further comprising a first BJT device including a first base terminal coupled to the output node and a first emitter terminal. The first BJT device operates at a first current density that is substantially proportional to absolute temperature. The curvature-corrected bandgap reference also includes a second BJT device including a second base terminal coupled to the output node and a second emitter terminal. The second BJT device operates at a second current density that is substantially independent of temperature. Finally the curvature-corrected bandgap reference includes a correction voltage proportional to a voltage difference of the first and second emitter terminals, wherein the correction voltage substantially cancels a curvature of the reference voltage.Type: GrantFiled: December 20, 2012Date of Patent: August 4, 2015Assignee: INVENSENSE, INC.Inventors: Derek Shaeffer, Nauman Afzal
-
Patent number: 9006832Abstract: A high-voltage MEMS system compatible with low-voltage semiconductor process technology is disclosed. The system comprises a MEMS device coupled to a high-voltage bias generator employing an extended-voltage isolation residing in a semiconductor technology substrate. The system avoids the use of high-voltage transistors so that special high-voltage processing steps are not required of the semiconductor technology, thereby reducing process cost and complexity. MEMS testing capability is addressed with a self-test circuit allowing modulation of the bias voltage and current so that a need for external high-voltage connections and associated electro-static discharge protection circuitry are also avoided.Type: GrantFiled: March 24, 2011Date of Patent: April 14, 2015Assignee: Invensense, Inc.Inventors: Derek Shaeffer, Baris Cagdaser, Joseph Seeger
-
Patent number: 8947081Abstract: A micromachined magnetic field sensor is disclosed. The micromachined magnetic field sensor includes a substrate; and a drive subsystem partially supported by the substrate with a plurality of beams, and at least one anchor; a mechanism for providing an electrical current through the drive subsystem along a first axis; and Lorentz force acting on the drive subsystem along a second axis in response to a magnetic field vector along a third axis. The micromachined magnetic field sensor also includes a position transducer to detect the motion of the drive subsystem and an electrostatic offset cancellation mechanism coupled to the drive subsystem.Type: GrantFiled: January 11, 2011Date of Patent: February 3, 2015Assignee: Invensense, Inc.Inventors: Joseph Seeger, Chiung C. Lo, Baris Cagdaser, Derek Shaeffer
-
Patent number: 8884710Abstract: A system and method in accordance with the present invention provides a gyroscope incorporating an improved PLL technique. The improved PLL auto-corrects its own reference low-frequency noise, thereby eliminating this source of noise, improving the noise performance of the gyroscope and allowing a compact implementation. The net result is a gyroscope with improved bias stability that can meet noise requirements with a smaller footprint.Type: GrantFiled: December 22, 2011Date of Patent: November 11, 2014Assignee: Invensense, Inc.Inventors: Derek Shaeffer, Ahingsa Soukhaphanith
-
Patent number: 8860409Abstract: A micromachined magnetic field sensor is disclosed. The micromachined magnetic field comprises a substrate; a drive subsystem, the drive subsystem comprises a plurality of beams, and at least one anchor connected to the substrate; a mechanism for providing an electrical current through the drive subsystem along a first axis; and Lorentz force acting on the drive subsystem along a second axis in response to a magnetic field along a third axis. The micromachined magnetic field sensor also includes a sense subsystem, the sense subsystem includes a plurality of beams, and at least one anchor connected to the substrate; wherein a portion of the sense subsystem moves along a fourth axis; a coupling spring between the drive subsystem and the sense subsystem which causes motion of the sense subsystem in response to the magnetic field; and a position transducer to detect the motion of the sense subsystem.Type: GrantFiled: January 11, 2011Date of Patent: October 14, 2014Assignee: Invensense, Inc.Inventors: Joseph Seeger, Chiung C. Lo, Baris Cagdaser, Derek Shaeffer
-
Patent number: 8841958Abstract: A charge pump circuit is disclosed. The charge pump circuit comprises a transfer capacitor receiving a first clock phase and a driving capacitor receiving a second clock phase, the second clock phase opposite to the first clock phase. The circuit includes a first switch coupling an input node to the transfer capacitor. The first switch being controlled by the driving capacitor. The circuit further includes a second switch coupling the input node to the driving capacitor. The second switch being controlled by the transfer capacitor. The circuit also includes a third switch coupling the transfer capacitor to an output node. The third switch being controlled by the driving capacitor. The third switch operating in phase opposition to the first switch. The circuit finally includes a charge storage capacitor coupled to the output node.Type: GrantFiled: March 11, 2013Date of Patent: September 23, 2014Assignee: InvenSense, Inc.Inventors: Derek Shaeffer, Baris Cagdaser
-
Publication number: 20140266256Abstract: A method and system for measuring displacement of a structure is disclosed. The method and system comprise providing a first capacitance and providing a second capacitance. The first and second capacitances share a common terminal. The method and system further include determining a difference of the inverses of the value of the first and second capacitances when the structure is displaced. The first capacitance varies in inverse relation to the displacement of the structure.Type: ApplicationFiled: July 26, 2013Publication date: September 18, 2014Applicant: InvenSense, Inc.Inventors: Baris CAGDASER, Du CHEN, Hasan AKYOL, Derek SHAEFFER