Marvell International Limited

Marvellworld Trade Ltd.

Foo Leng Leong

Ravishanker Krishnamoorthy

Edy Susanto

Cheng Yong Teoh

Siew Yong Chui

Yayue Zhang

Kiyotada Ito

Kuong Hoo, Legal Representative

Sakti Pada Rana

Yichao Wang

Takahiro Inoue

Kuno Shinichiro

Chen Yong Teoh

Cheng Yong Toeh

Siew Youn Chui

A system for controlling operation of a brushless DC motor is provided. The system includes a memory, driving profile and motor controllers, and an inverter. The memory stores: a scaling factor indicative of how much to increase an operating parameter of a base driving profile; and the base driving profile indicative of speed over time of a drive cycle of the brushless DC motor. The driving profile controller generates a motor driving profile, indicating an operating parameter for driving the brushless DC motor, where the operating parameter is based on (i) the scaling factor, and (ii) the base driving profile. The controller generates a control signal based on the operating parameter of the motor driving profile. The inverter: receives a direct current from a DC source; responsively to the control signal, converts the direct current to an alternating current; and drives the brushless DC motor via the alternating current.

Systems and methods for operating a brushless DC motor

A circuit comprises a position sensing circuit to sense first and second position states of a rotating object, a first counter storing a first counter value, and a second counter storing a second counter value. The first counter value is incremented when the position states are the same, the second counter value is incremented when the position states indicate that the rotating object has rotated in a direction, and a fault is indicated when either counter value is equal to or greater than their respective limits. A method comprises sensing two position states of a rotating object, incrementing a first counter value when the position states are the same, incrementing a second counter value when the rotating object is determined, using the position states, to have rotated in a direction, and indicating a fault when either counter value is equal to or greater than their respective limits.

Rotor lock detection

Some of the embodiments provide a method comprising: during an operation phase, operating a rotating device at a first speed; during the operation phase, monitoring a first current consumed by the rotating device to operate at the first speed; comparing the first current to a second current measured during a calibration phase while rotating the device at a second speed, wherein the first speed is substantially equal to the second speed; and based on comparing the first current and the second current, predicting a possible failure of the rotating device.

Failure prediction in a rotating device

A method for identifying a position of a multi-phase brushless motor includes applying a plurality of detection voltage pulses to the motor, each detection voltage pulse corresponding to a respective driving phase of the motor, measuring a time period associated with a current reaching a predetermined current limit for each applied detection voltage pulse, and identifying a driving phase associated with a shortest time period for the current to reach the predetermined current limit.

Identifying a position of a brushless DC motor

An integrated circuit for controlling operation of a motor of a fan assembly. The fan assembly includes a housing and a fan. The motor is in the housing. The housing is void of sensors. The motor is configured to rotate the fan. The integrated circuit includes a detection module and a first control module. The detection module is separate from the fan assembly. The detection module is configured to detect a voltage induced in a first coil of the motor or a back electromotive force received from the first coil of the motor. The first control module is configured to receive a control signal from a second control module and control the operation of the fan based on (a) the control signal, and (b) the voltage induced in the first coil of the motor or the back electromotive force. The second control module is separate from the integrated circuit.

Apparatuses for controlling operation of a motor of a fan assembly based on an induced voltage or a back electromotive force

Systems and methods to eliminate current surge during spindle spin up, include, in at least one aspect, a method including: using a duty cycle with a spindle motor to spin-up the spindle motor to achieve a steady-state operating speed for the spindle motor, wherein the spindle motor comprises phase windings; and using an adjusted version of the duty cycle for a period during the spin-up to reduce current surge onto a supply capacitor associated with the spindle motor during phase switching for the phase windings.

Method to eliminate current surge during spindle spin up

A system including memory to store a plurality of sets of values, where each set is used to control speed of a different type of motor. A pulse width modulation (PWM) module receives an input indicating a type of motor sensed in the system, selects a set corresponding to the type of the sensed motor, and generates, based on the selected set, a pulse width modulation signal to control speed of the sensed motor. A speed module receives a requested speed for the sensed motor and generates an output indicating a range of speed corresponding to the requested speed. The PWM module selects, based on the range of speed, a value from the selected set; shifts, based on the selected value, the pulse width modulation signal; and adjusts, based on the shifted pulse width modulation signal, the speed of the sensed motor by adjusting torque applied to the sensed motor.

Systems and methods for adaptive motor speed control

Embodiments of the present disclosure provide a method that comprises, based upon receipt of a mode command, changing an operating mode of a fan motor controller of a fan to a serial port communication protocol, programming a memory of the fan motor controller with an operating parameter of the fan, and based upon receipt of a serial port command, changing the operating mode of the fan motor controller from the serial port communication protocol to another protocol.

Systems and methods for programming of a cooling fan arrangement

Systems, methods, and other embodiments associated with back-EMF detection for motor control are described. In an embodiment, an apparatus includes a drive circuit configured to apply excitation signals to respective inputs of a motor, a signal inhibit circuit configured to convey a signal to inhibit application of the excitation signals during an interval, and a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval.

Back-EMF detection for motor control

A fan system includes a motor control module external to a motor housing of a fan assembly. The motor control module includes a speed control module. The fan assembly includes a fan and the motor housing. One or more first conductors are configured to connect the motor control module to a motor in the motor housing. One or more second conductors are configured to connect the motor control module to a host device control module. The host device control module is separate from the motor control module and is configured to generate a control signal. The speed control module is configured to control speed of the fan based on the control signal.

Apparatus and method for controlling speed of a fan via a first control module connected by a cable and/or conductors between a motor and a second control module

A system includes a target speed module and a pulse-width modulation (PWM) control module. The target speed module is configured to provide a first waveform based on a first speed setting for a motor. A start of a first cycle of the first waveform corresponds to at least one of a first current or a first voltage. The PWM control module is configured to shift a phase of the first waveform by a torque angle adjustment value to generate a second waveform. A start of a first cycle of the second waveform corresponds to at least one of a second voltage or a second current. The second voltage is greater than the first voltage, and the second current is greater than the first current. The PWM control module is configured to control the motor based on the second waveform.

Systems and methods for adaptive torque adjustment and motor control

According to an aspect of the invention, an apparatus includes: a spindle motor; and circuitry configured to spin up the spindle motor by increasing a command voltage in small steps while monitoring a current flowing through the spindle motor. According to another aspect of the invention, a method includes: spinning up a spindle motor from a stationary state to a target speed using a voltage mode of operation for the spindle motor, wherein the spinning up includes supplying to the spindle motor a series of multiple discrete voltage levels ranging from a first voltage level to a second voltage level; and maintaining the spindle motor at the target speed.

Voltage mode using pseudo current limit

A system including a monitoring module configured to monitor whether, during a first predetermined period, at least one of a read operation, a write operation, or a seek operation is performed on a platter of a storage device in response to the platter of the storage device rotating at a first speed. A speed control module is configured to rotate the platter of the storage device at a second speed in response to none of the read operation, the write operation, or the seek operation being performed on the platter of the storage device during the first predetermined period. The second speed is (i) less than the first speed, and (ii) greater than zero. None of the read operation, the write operation, or the seek operation is performed on the platter of the storage device in response to the platter of the storage device rotating at the second speed.

Speed control systems and methods for decreasing power consumption in rotating storage devices

In some implementations, a method includes receiving rotational speed information corresponding to a rotational speed of a spindle motor having a plurality of poles, down sampling the rotational speed information to obtain speed-related information associated with the spindle motor, and adjusting the rotational speed of the spindle motor based on the speed-related information.

Down sampling method for hard disk speed control loop

A control system and method for a multi-phase motor substantially reduces or eliminates jitter resulting from. drive mismatch by replacing a conventional trapezoidal drive profile with a drive profile that causes the voltage applied across active phases of the motor to match the back-EMF across those phases. In an ideal motor, the back-EMF is substantially sinusoidal, and although the drive profile applied to each phase is not truly substantially sinusoidal, the drive voltage across the active phases is substantially sinusoidal. In a non-ideal motor, the back-EMF is not truly sinusoidal and the drive profiles applied to each phase are calculated to cause the drive voltage across the active phases to match the back-EMF across those phases.

Growing community of inventors

Singapore, Singapore

Foo Leng Leong