Cirrus Logic Inc.

Analog Devices,inc.

Texas Instruments Corporation

Marc John Kobayashi

John L Melanson

Stephen James Sanchez

Bruce Eliot Duewer

Jason William Lawrence

Miroslav Olijaca

Branislav Pjetar

Michael Allan Kost

A Paul Brokaw

David Hisky

Tejasvi Das

Siddharth Maru

Jeffrey G Barrow

Michael Allen Kost

Bradley Allan Lambert

Rahul Gawde

Vitaliy Kulikov

Jason Matocha

Christian S Birk

Brad Allan Lambert

A method for determining sensor parameters of an actively-driven sensor system may include performing an initialization operation to establish a baseline estimate of the sensor parameters, obtaining as few as three samples of a measured physical quantity versus frequency for the actively-driven sensor system, performing a refinement operation to provide a refined version of the sensor parameters based on the as few as three samples, iteratively repeating the refinement operation until the difference between successive refined versions of the sensor parameters is below a defined threshold, and outputting the refined sensor parameters as updated sensor parameters for the actively-driven sensor system.

Determination of resonant frequency and quality factor for a sensor system

A method for generating a not-yet (NYET) signal in a recovered reference system for recovering a device reference clock on a device, wherein the NYET signal indicates that the device is not yet ready for transition into a low power mode, in order to improve a quality of a recovered reference clock representative of a host reference clock of a host communicatively coupled to the device, may be provided. The method may include detecting receipt of start-of-frame markers from the host to the device, responsive to detecting receipt of the markers, determining whether a condition for NYET generation is being met, responsive to the condition for NYET generation being met, generating the NYET signal to cause the host to continue generating the markers, and responsive to the condition for NYET generation not being met, causing the device to generate an acknowledge signal for transition of the device into the low power mode.

Recovery of reference clock on a device

A device may include an input for receiving information communicated from a host to the device and a controller configured to recover a device reference clock on the device, the device reference clock proportional to a host reference clock of the host, when clock signaling from the host to the device is unavailable. The controller may recover the device reference clock by measuring a ratio between the host reference clock and the device reference clock of the device by monitoring, with the device, host start-of-frame markers communicated from the host to the device via the input, creating a recovered reference clock based on the measured ratio, and creating local start-of-frame markers that are phase locked with the host start-of-frame markers based on the recovered reference clock.

A method of generating asynchronous feedback information for asynchronous, isochronous audio communication may include determining a relative change of stored samples in a device and generating the asynchronous feedback information provided to a host from the device based on the relative change. A method of generating asynchronous feedback information for asynchronous, isochronous audio communication may include determining a relative phase of a host clock for a host and a device clock for a device and generating the asynchronous feedback information provided to the host from the device based on the relative phase.

Asynchronous positional feedback for asynchronous and isochronous communication

The system contains a controller unit comprising a memory device, a processing unit, and at least one analog-to-digital converter. A power stage has a plurality of switches, wherein the power stage receives a control signal from the control circuit and a power signal from a power source. The power stage drives two windings of the set of three stator windings to rotate a rotor and maintains one stator winding of the three stator windings undriven. The memory device stores a plurality of values for the driven current and a plurality of demodulated undriven winding voltages. The processing unit compares the plurality of values and periodically calculates a rotor sextant while the rotor rotates. The processing unit compares at least two demodulated undriven winding voltage values corresponding to at least two current values within the rotor sextant to calculate the rotor sextant parity and verify the calculation of the rotor sextant.

Circuit and method for detecting missed commutation of a brushless DC motor

A system is disclosed for controlling motor switching in a sensorless BLDC motor having a set of three stator windings. A controller unit includes a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage having a plurality of switches receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with an asymmetric pulse width modulation signal and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit also communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.

Determining commutation position for a sensorless permanent magnet brushless motor at low or zero speed using an asymmetric drive pattern

A system for controlling motor switching in a sensorless BLDC having a stator with three stator windings and a permanent magnet rotor. The system includes a controller unit comprising a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage controlled by the controller unit has a plurality of switches and drives two windings of the three stator windings with a pulse width modulation signal and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit calculates a threshold at which the power stage will change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses the threshold.

Circuit and method for calibration of sensorless control of a permanent magnet brushless motor during start-up

The system and method disclose for the controlling of motor switching. The system includes a controller unit having a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage has a plurality of switches and receives a control signal from the control signal generator and a power signal from a power source. The power stage drives two windings of the set of three stator windings with a multi-state pulse and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit communicates with the power stage to change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses a threshold.

Method and system for switching between different types of operation of a sensorless permanent magnet brushless motor at low or zero speed to determine rotor position

The system discloses structure for synchronizing sequential phase switching in driving a set of stator windings of a multi-phase sensorless brushless permanent magnet DC motor. A drive voltage drives a plurality of the stator windings thereby producing a magnetic field. On an undriven stator winding among the stator windings, a voltage induced by the magnetic field is sampled. The induced voltage changes as a function of a magnetic rotor transitioning across a plurality of angular positions. A first value corresponding to the sampled voltage induced on the currentless winding is compared with a commutation threshold to determine a proper commutation point. The system is switched to a next drive configuration of the sequence when the first value surpasses the threshold.

Circuit and method for sensorless control of a permanent magnet brushless motor during start-up

The system and method disclose for the controlling of sequential phase switching in driving a set of stator windings of a multi-phase sensorless brushless permanent magnet DC motor. A motor controller controls a power stage that drives two windings of a set of three windings in the motor with pulse width modulated signal. A plurality of voltage values on an undriven winding of the set of three windings are sampled within a window of time, wherein a period beginning when the driven windings are energized and ending when the driven windings are de-energized encompasses the window of time. The sampled voltage values are processed. When the processed voltage values exceed a threshold, the motor controller changes which two windings are driven.

System and method for isolating the undriven voltage of a permanent magnet brushless motor for detection of rotor position

A linearized controller to operate a switching power converter which includes an inductor having its first terminal coupled to a first voltage (V) and its second terminal switched so that it alternately connects to a second, higher voltage (V) or to a common terminal. A sawtooth voltage generator produces a ramp voltage (V) having a period T and an amplitude which varies in response to a control voltage Vx, and a voltage comparator which compares Vto a control voltage Vy. The comparator output controls the switching such that T is divided into intervals tand t, during which the second terminal is connected to the common terminal or to V, respectively. When Vy is maintained in a fixed proportion to V, Vis driven to be in the same proportion to Vx, independently of changes in V, providing a boost converter. A buck converter is similarly realized.

Linearized controller for switching power converter

A switching voltage converter, suitably a boost converter, employs an n-type transistor, preferably an NMOS FET, as a series switch, with its drain coupled to the cathode of the converter's diode and its source coupled to the converter's output node. A charge pump driven by the converter's switching voltage provides a voltage Vat the NMOS FET's gate input sufficient to turn the FET on. A series switch controller is arranged to, in response to a control signal, hold the NMOS FET off such that the converter's output voltage Vis approximately zero regardless of the status of input voltage V, or allow the NMOS device to be turned on by V.

Boost converter with series switch

A circuit for boosting an input voltage (V ) to provide a low ripple output voltage (V ) regulates flow of current between a source of the input voltage (V ) and a circuit node ( ) in response to a feedback signal ( ) representative of the output voltage (V ). A charge pump circuit operates to repetitively charge a pump capacitor (C ) to a voltage equal to the input voltage (V ) and redistribute charge between the pump capacitor (C ) and a level-shifting capacitor (C ) coupled between the circuit node ( ) and an output conductor ( ) conducting the output voltage (V ) so as to maintain the boosted output voltage (V ).

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Oro Valley, AZ, United States of America

Marc John Kobayashi