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公开(公告)号:US20190379984A1
公开(公告)日:2019-12-12
申请号:US16549625
申请日:2019-08-23
Inventor: Hynek SAMAN , James Thomas DEAS
Abstract: This applications relates to methods and apparatus for amplifying signals from capacitive transducers, in particular MEMS transducers such as MEMS capacitive microphones. An amplifier circuit has a signal node for receiving the input signal, a transducer biasing node for outputting a transducer bias voltage for biasing the capacitive transducer, and a voltage buffer configured to generate a buffered bias voltage at a buffer node. An amplifier arrangement is configured to receive the input signal from the signal node and the buffered bias voltage. The amplifier circuit comprises a signal path for supplying the buffered bias voltage to the transducer biasing node via a first capacitance, and the amplifier arrangement comprises a feedback resistor network configured such that: a change in input signal with respect to the buffered bias voltage results in a change in the output signal with respect to the buffered bias voltage with a gain greater than one; and a change in the buffered bias voltage results in a change in the output signal with a gain equal to one.
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公开(公告)号:US20170180853A1
公开(公告)日:2017-06-22
申请号:US15131886
申请日:2016-04-18
Inventor: Jaimin MEHTA , James Thomas DEAS , Stephen T. HODAPP , Brian Parker CHESNEY
CPC classification number: H04R3/007 , H04R19/005 , H04R29/004 , H04R2201/003
Abstract: A system may include control circuitry for detecting a plosive event associated with a microphone transducer and in response to the plosive event, causing restoration of acoustic sense operation of the microphone transducer and a processing circuit associated with the microphone transducer. A system for configuring a filter having at least two frequency response configurations to achieve an effective frequency response configuration intermediate to the at least two frequency response configurations may include control circuitry for rapidly switching between the at least two frequency response configurations such that a weighted average frequency response of the filter corresponds to the effective frequency response configuration.
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公开(公告)号:US20190020962A1
公开(公告)日:2019-01-17
申请号:US16136939
申请日:2018-09-20
Inventor: James Thomas DEAS , Scott Lyall CARGILL
Abstract: The application describes a MEMS transducer in which first and second conductive elements of a capacitor are both provided on the membrane. The membrane is shaped that the first and second conductive elements are displaced relative to each other when the flexible membrane deflects in response to a pressure differential across the membrane. For example the membrane may be corrugated.
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公开(公告)号:US20180301920A1
公开(公告)日:2018-10-18
申请号:US15951240
申请日:2018-04-12
Inventor: James Thomas DEAS , Paul WILSON
Abstract: Devices are disclosed including a transducer device comprising a first circuit for operating a MEMS transducer and connected to a supply terminal for receiving a power supply voltage, and a power consumption levelling circuit for dissipating a correction power and arranged to adjust the correction power to at least partially offset a change in power consumption of the first circuit due to a change in the power supply voltage.
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公开(公告)号:US20190306621A1
公开(公告)日:2019-10-03
申请号:US15939994
申请日:2018-03-29
Inventor: Ian Johnson SMITH , James Thomas DEAS , Vivek SARAF
Abstract: The present disclosure relates to a protection system for protecting a MEMS transducer of a MEMS device from electrostatic capture, wherein the MEMS transducer is operable in a normal-sensitivity, mode and in a reduced-sensitivity mode. The protection system comprises: an overload detector for detecting an overload condition arising as a result of an excessive sound pressure level at the MEMS transducer; a signal estimator configured to generate an estimate of a sound pressure level at the MEMS transducer; and a controller configured, in response to detection by the overload detector of an overload condition, to: disable an output of the MEMS transducer; and after a delay of a first predetermined period of time: cause the MEMS transducer to operate in the reduced-sensitivity mode; enable the output of the MEMS transducer; and cause the MEMS transducer to return to the normal-sensitivity mode if the estimate of the sound pressure level generated by the signal estimator while the MEMS transducer is operating in the reduced-sensitivity mode is below a safe sound pressure level threshold for a second predetermined period of time.
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公开(公告)号:US20180035229A1
公开(公告)日:2018-02-01
申请号:US15660508
申请日:2017-07-26
Inventor: James Thomas DEAS , Scott Lyall CARGILL
CPC classification number: H04R31/006 , B81B3/0021 , B81B2201/0257 , B81B2203/0127 , B81B2203/04 , B81C1/00158 , H04R9/046 , H04R19/005 , H04R19/02 , H04R19/04 , H04R2201/003 , H04R2499/11
Abstract: The application describes a MEMS transducer in which first and second conductive elements of a capacitor are both provided on the membrane. The membrane is shaped that the first and second conductive elements are displaced relative to each other when the flexible membrane deflects in response to a pressure differential across the membrane. For example the membrane may be corrugated.
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公开(公告)号:US20200055726A1
公开(公告)日:2020-02-20
申请号:US16603740
申请日:2018-04-12
Abstract: Micro-electro-mechanical system (MEMS) devices are disclosed, including a MEMS device comprising a semiconductor die including integrated circuitry, a structure mounted on the semiconductor die and covering at least a portion of the circuitry, the structure defining a space between the structure and the at least a portion of the circuitry, and a transducer including a membrane, the transducer located outside of the space.
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公开(公告)号:US20180302727A1
公开(公告)日:2018-10-18
申请号:US15946590
申请日:2018-04-05
Inventor: James Thomas DEAS
CPC classification number: H04R19/04 , H04R1/04 , H04R19/005 , H04R2201/003 , H04R2410/05 , H04R2499/11
Abstract: MEMS devices are disclosed including a MEMS microphone device comprising a first transducer adjoining a sound port, a second transducer not adjoining a sound port, a housing defining a shared volume for the first and second transducers, and circuitry arranged to combine a first signal from the first transducer and a second signal from the second transducer to produce an output signal.
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公开(公告)号:US20170284825A1
公开(公告)日:2017-10-05
申请号:US15628057
申请日:2017-06-20
Inventor: John Paul LESSO , Emmanuel Philippe Christian HARDY , James Thomas DEAS , Toru IDO
IPC: H04R3/06 , G01D5/24 , G01D5/244 , G01P15/125 , H03M1/06 , H03M3/00 , H04R19/00 , H04R19/04 , G01D3/02 , G01P15/08 , H03M1/12 , H04R29/00
CPC classification number: H04R3/06 , G01D3/02 , G01D5/24 , G01D5/24476 , G01P15/125 , G01P2015/0865 , H03M1/0609 , H03M1/12 , H03M3/352 , H03M3/458 , H04R19/005 , H04R19/04 , H04R29/004 , H04R2201/003 , H04R2499/11
Abstract: This application relates to circuitry for processing sense signals generated by MEMS capacitive transducers for compensating for distortion in such sense signals. The circuitry has a signal path between an input (204) for receiving the sense signal and an output (205) for outputting an output signal based on said sense signal. Compensation circuitry (206, 207) is configured to monitor the signal at a first point along the signal path and generate a correction signal (Scorr); and modify the signal at at least a second point along said signal path based on said correction signal. The correction signal is generated as a function of the value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal. The first point in the signal path may be before or after the second point in the signal path. The monitoring may be performed in an analogue or a digital part of the signal path and in either case the modification may be applied in an analogue or a digital part of the signal path.
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