Marvell International Limited

Marvellworld Trade Ltd.

Cheng Yong Teoh

Foo Leng Leong

Edy Susanto

Ravishanker Krishnamoorthy

Siew Yong Chui

Yayue Zhang

Ying Tian Li

Sakti Pada Rana

Kuong Hoo, Legal Representative

Rudy Kurniawan

Kuno Shinichiro

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

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

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

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

A control system includes a position control module, a power control module, and a diagnostic module. The position control module applies a driving current for positioning a rotor of a motor at one of first and second positions. The power control module applies a first voltage to one of first and second phases of the motor to generate a first current after the position control module applies the driving current to position the rotor at the first position. The power control module applies a second voltage to one of the first and second phases to generate a second current after the position control module applies the driving current to position the rotor at the second position. The diagnostic module determines when the rotor is restricted from rotating based on the first and second currents.

Determining stuck conditions for electric motors using inductive sensing

A control system for a fan includes a control housing that is external to a fan housing for the fan. At least one fan control module is within the control housing and communicates remotely with terminals within the fan housing via at least one wire. The at least one fan control module includes a detection module. The detection module detects induced voltages in at least one of a plurality of stator coils within the fan housing via the at least one wire without receiving signals from a sensor in the fan housing.

Fan motor control systems

In one embodiment the present invention includes a circuit comprising a switch and a switch driver. The switch is configured to provide synchronous rectification switching of a back-EMF voltage. The synchronous rectification switching produces a source voltage. The switch driver is configured to receive the back-EMF voltage and the source voltage. The switch driver provides a control signal to a control terminal of the switch. The control signal has a frequency. The frequency is used to control an amount of the synchronous rectification switching. Accordingly, the frequency reduces a dissipated power associated with the synchronous rectification switching.

Systems and methods for reducing spindle rectification switching

A system for controlling a rotational speed of a platter in a storage device. The system includes a mode selection module configured to select a mode operation for the storage device, in which the mode of operation includes at least i) a read/write mode in which data is to be read from or written to the platter, ii) a standby mode during in which data is not to be read from or written to the platter, or iii) a shutdown mode. The system further includes a speed control module configured to control the rotational speed of the platter based on the selected mode of operation for the storage device.

The power required by a voice coil motor (VCM) to maintain the head in the data region of a disk drive during an idle mode is further reduced. The current supplied to the VCM is switched on and off. This takes advantage of the inherent capacitance and inductance in the VCM, which maintains a current after the current supply is switched off. The current will slowly decay, with it being switched on again before it reaches a level where the average value won't offset the flex bias. In one embodiment, the current is maintained in a single direction, to offset the flex bias which pushes in one direction. Digital switches are used to reduce the power consumption of the control circuitry.

VCM PWM control architecture for power saving in hard disk drives

A speed control system for a rotating storage device including a mode selection module configured to select an operating mode or a standby mode to operate the rotating storage device based on use of the rotating storage device and to select the standby mode after a first predetermined period during which reading and writing to the rotating storage device is not performed. The first predetermined period is selected based on a type of device in which the rotating storage device is implemented. The speed control system includes a speed control module configured to select a predetermined operating speed to rotate a storage medium of the rotating storage device when the operating mode is selected and to select a predetermined standby speed to rotate the storage medium when the standby mode is selected. The predetermined standby speed is (i) less than the predetermined operating speed and (ii) greater than zero.

The power required by a voice coil motor (VCM) to maintain the head in the data region of a disk drive during an idle mode is further reduced. The current supplied to the VCM is switched on and off. This takes advantage of the inherent inductance in the VCM, which maintains a current after the current supply is switched off. The current will slowly decay, with it being switched on again before it reaches a level where the average value won't offset the flex bias. In one embodiment, the current is maintained in a single direction, to offset the flex bias which pushes in one direction. Digital switches are used to reduce the power consumption of the control circuitry.

A driver for a motor in a device includes a reference generator to generate a reference value. A clock management module receives a plurality of clock signals. Each clock signal has a corresponding frequency that is different relative to the corresponding frequency of another clock signal. A clock management module selects a different clock signal of the plurality of clock signals for output from the clock management module at different times during operation of the device. A ramp generating module generates a ramp signal in accordance with the corresponding frequency associated with the selected clock signal. A first pulse width modulation module receives the reference signal and the ramp signal. The first pulse width modulation module outputs a first pulse width modulation driver signal for driving the motor based on the reference signal and the ramp signal.

Adjustable frequency PWM driver

A spindle/voice coil motor (VCM) driver includes a clock management module that receives a system clock signal and a second clock signal, and that selects one of the system clock signal or the second clock signal as a selected clock signal. A reference generating module generates a reference signal. A ramp generating module receives the selected clock signal and generates a ramp signal. A pulse width modulation (PWM) module receives the reference signal and the ramp signal and outputs a first PWM driver signal based thereon.

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Singapore, Singapore

Cheng Yong Teoh