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公开(公告)号：US11652455B2
公开(公告)日：2023-05-16
申请号：US17173813
申请日：2021-02-11
Inventor： Ravi K. Kummaraguntla , Christophe J. Amadi , John L. Melanson , Axel Thomsen , John C. Tucker , Eric J. King
IPC: H03F3/387 , G01R31/3842 , G01R31/40 , H03F3/181
CPC classification number: H03F3/387 , G01R31/3842 , G01R31/40 , H03F3/181 , H03F2200/03 , H03F2200/375
Abstract: A signal processing system may include a signal path and a chop management circuit. The signal path may comprise a chopper configured to chop a differential input signal to the signal path at a chopping frequency and a low-pass filter downstream of the chopper and configured to filter out intermodulation products of a direct current offset of the signal path and intermodulation products of an aggressor on the differential input signal in order to generate an output signal. The chop management circuit may be communicatively coupled to the chopper and configured to, based on operational parameters associated with the signal path, dynamically manage energy of one or more clock signals used to define the chopping frequency.
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公开(公告)号：US10511923B2
公开(公告)日：2019-12-17
申请号：US15938665
申请日：2018-03-28
Inventor： Jean Pierre Lasseuguette , Aleksey Sergeyevich Khenkin , Axel Thomsen
Abstract: The disclosure provides a system, comprising: a MEMS capacitive transducer, comprising one or more first capacitive plates coupled to a first node and one or more second capacitive plates coupled to a second node; biasing circuitry coupled to the first node, operable to provide a biasing voltage to the one or more first capacitive plates; and test circuitry coupled to the second node, operable to: selectively apply one or more current sources to the second node, so as to charge and discharge the MEMS capacitive transducer and so vary a signal based on a voltage at said second node between an upper value and a lower value; determine a parameter that is indicative of a time period of the variation of the signal; and determine a capacitance of the MEMS capacitive transducer based on the parameter that is indicative of the time period.
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公开(公告)号：US20180335458A1
公开(公告)日：2018-11-22
申请号：US15598582
申请日：2017-05-18
Inventor： John L. Melanson , Anindya Bhattacharya , Axel Thomsen , Eric Smith , Vamsikrishna Parupalli , Mark May , Johann Gaboriau , Junsong Li
CPC classification number: G01D5/24 , G01R27/2605
Abstract: Sensing electronics may be used to measure capacitance of components, such as speakers in mobile devices. A sensing circuit may include a charge-sense front end with sine wave excitation, an analog-to-digital conversion block, and a digital demodulator. The component being measured by the sensing electronics may be excited by a high-frequency sine wave excitation. The digitization of the output from the component may be performed using a bandpass filter synchronized with the excitation signal by centering the bandpass filter near (e.g., within 5% of) the frequency of the excitation signal.
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公开(公告)号：US20180324525A1
公开(公告)日：2018-11-08
申请号：US15586023
申请日：2017-05-03
Inventor： Vivek Saraf , Axel Thomsen , Ravi Kummaraguntla , John C. Tucker
CPC classification number: H04R3/04 , H03F3/185 , H03F2200/03 , H03F2200/18 , H03H7/40 , H04R3/00 , H04R2201/003
Abstract: Input impedance biasing may be improved with an ultra-high-input-impedance biasing circuit having low temperature variation. The impedance biasing circuit may include a first transistor coupled to a first power supply and a second transistor coupled to a second power supply. A gate of the first transistor may be coupled to a gate of the second transistor at an intermediate bias node. The first transistor and the second transistor may provide a selected DC impedance at the intermediate bias node. The impedance may be used to provide low-pass and or high-pass filtering of audio signals and/or noise.
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公开(公告)号：US10123117B1
公开(公告)日：2018-11-06
申请号：US15586023
申请日：2017-05-03
Inventor： Vivek Saraf , Axel Thomsen , Ravi Kummaraguntla , John C. Tucker
CPC classification number: H04R3/04 , H03F3/185 , H03F2200/03 , H03F2200/18 , H03H7/40 , H04R3/00 , H04R2201/003
Abstract: Input impedance biasing may be improved with an ultra-high-input-impedance biasing circuit having low temperature variation. The impedance biasing circuit may include a first transistor coupled to a first power supply and a second transistor coupled to a second power supply. A gate of the first transistor may be coupled to a gate of the second transistor at an intermediate bias node. The first transistor and the second transistor may provide a selected DC impedance at the intermediate bias node. The impedance may be used to provide low-pass and or high-pass filtering of audio signals and/or noise.
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Patent Agency Ranking
26.发明授权公开(公告)号：US09900707B1
公开(公告)日：2018-02-20
申请号：US15363798
申请日：2016-11-29
Inventor： Axel Thomsen
CPC classification number: H04R19/04 , H03G3/3005 , H04R3/06 , H04R7/04 , H04R19/005 , H04R29/004 , H04R2201/003
Abstract: A MEMS microphone may include a backplate comprising first and second electrodes electrically isolated from one another and mechanically coupled to the backplate in a fixed relationship relative to the backplate and a diaphragm configured to displace relative to the backplate as a function of sound pressure incident upon the diaphragm, the diaphragm comprising third and fourth electrodes electrically isolated from one another and mechanically coupled to the diaphragm in a fixed relationship relative to the diaphragm such that the third and fourth electrodes displace relative to the backplate as a function of sound pressure incident upon the diaphragm. The first and third electrodes may form a first capacitor and the second and fourth electrodes may form a second capacitor, the capacitance of each which may be a function of the displacement of the diaphragm, and each of which may be biased by an alternating-current voltage waveform.
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公开(公告)号：US12047097B2
公开(公告)日：2024-07-23
申请号：US17885126
申请日：2022-08-10
Inventor： Arashk Norouzpourshirazi , Stephen T. Hodapp , Ravi K. Kummaraguntla , Paul Wilson , Axel Thomsen
CPC classification number: H03M3/496 , G11C27/024 , H02M3/07 , H03K17/063 , H03M1/1245 , H02M3/076
Abstract: A system may include a switched-capacitor analog front end comprising a plurality of switches for sampling an analog physical quantity and a bootstrap generation network electrically coupled to the plurality of switches and configured to generate a bootstrap sampling clock for controlling the plurality of switches and generate a floating supply voltage for the bootstrap sampling clock based on the analog physical quantity.
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公开(公告)号：US11368151B2
公开(公告)日：2022-06-21
申请号：US17349536
申请日：2021-06-16
Inventor： John L. Melanson , Eric J. King , Thomas H. Hoff , Axel Thomsen
IPC: H03B1/00 , H03K3/00 , H03K17/687 , H02N2/00 , H02M3/158
Abstract: This application relates to methods and apparatus for driving a transducer with switching drivers where the switching driver has an output bridge stage for switching an output node between switching voltages and a modulator for controlling the duty cycle of the output bridge stage based on an input signal. The switching driver also includes a voltage controller for providing the switching voltages which is operable to provide different switching voltages in different driver modes. A controller is provided to control the driver mode of operation and the duty cycle of the switching driver based on the input signal, and the controller is configured to transition from a present driver mode to a new driver mode by controlling the voltage controller to provide the switching voltages for the new mode and controlling the modulator to vary the duty cycle of the output bridge stage. The change in duty cycle is controlled such that there is no substantial discontinuity in switching ripple due to the mode transition.
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公开(公告)号：US10460819B2
公开(公告)日：2019-10-29
申请号：US15365451
申请日：2016-11-30
Inventor： Ramin Zanbaghi , Tejasvi Das , John L. Melanson , Axel Thomsen
Abstract: A variable resistor may be coupled between a reference voltage source and components of an integrated circuit to reduce issues relating to thermal noise from a reference voltage signal generated by the reference voltage source. The variable resistor may be set to a low level during a first time period and a high level during a second time period, in which the time periods correspond to a sampling period of a switched-capacitor circuit. The low resistance time period may allow quick settling of an input reference voltage signal, whereas the high resistance time period may reduce a bandwidth of noise on a sampling capacitor coupled to the reference voltage signal. The variable resistor and switched-capacitor network may be used in an analog-to-digital converter (ADC), such as in audio circuits.
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30.发明授权公开(公告)号：US09813831B1
公开(公告)日：2017-11-07
申请号：US15363863
申请日：2016-11-29
Inventor： Axel Thomsen
CPC classification number: H04R29/004 , H04R3/06 , H04R19/005 , H04R19/04 , H04R2201/003
Abstract: A MEMS may include a backplate comprising first and second electrodes electrically isolated from one another and mechanically coupled to the backplate in a fixed relationship relative to the backplate, and a diaphragm configured to mechanically displace relative to the backplate as a function of sound pressure incident upon the diaphragm. The diaphragm may comprise third and fourth electrodes electrically isolated from one another and mechanically coupled to the diaphragm in a fixed relationship relative to the diaphragm such that the third and fourth electrodes mechanically displace relative to the backplate as the function of the sound pressure. The first and third electrodes may form a first capacitor, the second and fourth electrodes may form a second capacitor, and the first capacitor may be configured to sense a displacement of the diaphragm responsive to which the second capacitor may be configured to apply an electrostatic force to the diaphragm to return the diaphragm to an original position.
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