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公开(公告)号：US11888492B2
公开(公告)日：2024-01-30
申请号：US17683650
申请日：2022-03-01
发明人： Jianping Wen , John L. Melanson
IPC分类号： H03M1/06
CPC分类号： H03M1/0607
摘要： A background offset calibration system for an analog signal comparator provides low offset without compromising tracking bandwidth. The comparator includes a preamplifier and a decision latch. A switching selectively couples outputs of an analog circuit to the inputs of the preamplifier stage. A state control logic alternatively operates the system in a first phase in which the analog circuit acquires an input signal while the comparator is calibrated, and a second phase in which a comparison is performed by the comparator. In the first phase, the switching circuit disconnects the outputs of the analog circuit from the preamplifier stage and applies a common mode reference to the inputs of the preamplifier. An offset correction circuit determines correction changes from a history of states of the decision latch across multiple sampling cycles. The offset correction circuit adjusts a threshold voltage of the decision latch by applying the correction changes.
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公开(公告)号：US11777517B2
公开(公告)日：2023-10-03
申请号：US17096582
申请日：2020-11-12
IPC分类号： H03M3/00
摘要： An integrated circuit having multiple switched-capacitor delta-sigma data converter circuits includes compensation for voltage reference error due to leakage current that causes reference voltage droop. The reference filter capacitor terminal voltage is maintained by periodic connection to the reference feedback capacitor(s) that are alternately connected to a voltage reference buffer, and the leakage into the reference feedback capacitor networks of disabled converter circuits causes reference voltage droop. The compensation is either determined from the number of converter circuits that are disabled, or from an error between the filter capacitor voltage and a separate voltage reference, and may be applied by adjusting a resistance selectively coupled between the voltage reference buffer output and the filter capacitor, feedback applied to the voltage reference buffer or its input source. Alternatively, or in combination, correction may be applied to the output of the active converters by digital adjustment of output values.
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公开(公告)号：US11677360B2
公开(公告)日：2023-06-13
申请号：US17521268
申请日：2021-11-08
发明人： Leyi Yin , John L. Melanson , Eric Lindemann , Amar Vellanki , Jianhao Chen , Venugopal Choukinishi , Wai-Shun Shum , Xiaofan Fei
CPC分类号： H03F3/183 , H04R3/04 , H04R29/001 , H03F2200/03 , H04R2430/01
摘要： A multi-path audio amplification system that provides an output drive signal to electromechanical output transducers provides improved undistorted headroom, reduced path switching noise, and/or improved frequency response performance. Multiple signal amplification paths receive an audio input signal and have corresponding multiple output stages that have differing output impedances. A mode selector selects an active one of the multiple signal amplification paths is selected to supply the output drive signal. Outputs of the multiple output stages are coupled to the electromechanical transducer to provide the output drive signal and at least one of the multiple signal amplification paths includes an equalization filter for filtering the audio input signal to compensate for phase or gain differences referenced from the input to the outputs of the multiple output stages due to interaction between the differing output impedances and an impedance of the electromechanical transducer.
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公开(公告)号：US11231732B1
公开(公告)日：2022-01-25
申请号：US16922654
申请日：2020-07-07
摘要： A power managed voltage reference quickly provides accurate operation when enabled and also avoids back-charging power supply rails when disabled. When disabled, the voltage reference filter capacitor is decoupled from the voltage reference buffer and coupled to a pre-charge source having a voltage magnitude greater than the reference voltage. When the voltage reference is enabled, the capacitor is coupled to a discharge path and the voltage across the capacitor is detected to determine when to decouple the capacitor from the discharge path and couple the capacitor to the voltage reference buffer. The capacitor voltage is also detected while disabling the voltage reference. Back-charging the pre-charge supply is prevented by coupling the capacitor to the discharge path until the magnitude of the capacitor voltage is less than the lowest voltage specified for the pre-charge supply, then coupling the capacitor to the pre-charge supply to prepare for enabling the voltage reference.
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公开(公告)号：US11102583B1
公开(公告)日：2021-08-24
申请号：US16829286
申请日：2020-03-25
发明人： Anthony S. Doy , Jeffrey A. May
摘要： An audio power output circuit provides a pair of output signals to an audio output transducer that has two different voice coils. Using a measured or predicted position of the voice coil assembly with respect to the transducer's magnetic field, a processing circuit generates the pair of signals such that a first relationship between a first one of the pair of output signals and an audio input signal and a second relationship between a second one of the pair of the output signals vary with the position of the voice coil. Offset in the Dynamic Mean Position (DMP) can be compensated for without adding low frequency or direct current components that compromise the dynamic range of the transducer. The efficiency, acoustic output power and/or linearity of the acoustic output of the transducer may be optimized by tailoring the first and second relationship to a particular target performance.
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公开(公告)号：US11057727B2
公开(公告)日：2021-07-06
申请号：US16987631
申请日：2020-08-07
发明人： Tian Zhao , Jeffrey A. May
摘要： An audio or haptic power output system manages and delivers power to multiple output transducers based on corresponding power or current limits that are adjusted dynamically according to measures of power or current that are required to generate power output signals from corresponding digital input values or signals. A power management subsystem controls electrical power or current consumed by power output stages that supply power to the transducers by comparing the measures of power or current required to generate the power output signals to the corresponding power or current limits, and limiting the power or current consumed by the individual power output stages measures of power or current exceeds the corresponding limits.
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公开(公告)号：US10894262B1
公开(公告)日：2021-01-19
申请号：US15639537
申请日：2017-06-30
申请人： Steven C. Cooper
发明人： Steven C. Cooper
摘要： An electrostatic sprayer system for dispensing and dispersing a liquid containing a spray compound includes a spray cloud dispersal feature that reduces the time that a residual spray cloud containing droplets including the spray compound remains suspended after spraying. A method of dispersing the residual spray cloud is implemented by a control system that causes a flow control system to deliver a non-active gas or liquid in conjunction with stopping delivery of the liquid containing the spray agent and charged with the same polarity, so that a charged cloud of the non-active gas or liquid, which may be air, displaces the suspended active fluid particles. The non-active gas or liquid may be dispensed for a predetermined time interval as determined by the control system, or the operator may control the time interval during which that the non-active fluid is dispensed.
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公开(公告)号：US10827076B1
公开(公告)日：2020-11-03
申请号：US16815936
申请日：2020-03-11
发明人： Ying Li , Venkat Anant , Wilbur Lawrence , Seth Suppappola
摘要： An acoustic echo path change detector provides a monitoring process in an acoustic echo canceler that removes echo from a microphone signal using an adaptive echo path model that generates an echo estimate from a playback signal. The acoustic echo canceler removes the echo estimate from the microphone signal to provide an echo-canceled output signal. The path change detector receives the microphone signal, the echo estimate and the output signal and determines a rate of change of one or more statistical values dependent on the microphone signal, the echo estimate and the output signal. If the rate of change exceeds a threshold value, the echo path change detector generates an indication that causes a supervisory process to change adaptation of the adaptive echo path model to increase responsiveness to the change in the acoustic echo path, e.g., by increasing the step size.
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公开(公告)号：US10743135B2
公开(公告)日：2020-08-11
申请号：US16557277
申请日：2019-08-30
摘要： A mobile wireless network and a method of operation provide analysis of mobile wireless device communications and suggested corrective initiated upon detecting communications performance issues. In some embodiments, the operations include blocking access to location information pertaining to a mobile wireless device based on the state of access flag that is maintained in the network for the mobile wireless device.
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公开(公告)号：US10564101B1
公开(公告)日：2020-02-18
申请号：US16179254
申请日：2018-11-02
申请人： Optomak, Inc.
摘要： A multi-site fluorescence recording system provides simultaneous monitoring of cell activity in different brain regions of a freely moving animal. The system includes an electrical rotary joint that couples signals to and from an external data acquisition and control unit connected to a stator of the rotary joint, which releases twisting of the optical fibers connected to the animal. Electrical signals are coupled to one or more fluorescence stimulation/detection units on the rotor of the rotary joint. The fluorescence stimulation/detection units receive one or more connections from optical fibers that connect the stimulation/detection unit(s) to the different brain sites. The rotating stimulation/detection units include spectral filters to separate the excitation light from the fluorescence signal, light sensors (an image sensor or photodiodes) and excitation light sources.
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