Abstract: A circuit for regulating voltage in a power driver, the circuit comprising a current amplifier adapted to measure current flowing through an input resistor, separate AC and DC components of the current flowing through an input resistor, and apply an AC gain factor to the AC component and a DC gain factor to the DC component.

Abstract: An improved CMBB regulator includes a current amplifier circuit that allows both load transient performance and noise immunity to be optimized simultaneously. The current amplifier circuit measures a voltage drop across a sense resistor to determine a power driver output current. The current amplifier circuit separates AC and DC current information and applies separate gain factors to the AC and DC current information. AC and DC current information modified by the gain factors is then recombined and used to pass current through an output resistor. A current amplifier output voltage is input to a comparator circuit that provides an output that indicates whether the current amplifier output voltage is above, equal to, or below a desired voltage level. The comparator output is then used to provide feedback control to a power driver circuit.

Abstract: A current controller for a device is provided. The current controller includes power and ground inputs for connecting to a source of energization, and power and ground outputs for connecting to the device. A variable impedance is coupled in series between the power input and the power output and has an impedance control input. The impedance control input controls the variable impedance between a high impedance, OFF state and a low impedance, ON state. An impedance control circuit is coupled to the impedance control input, which biases the variable impedance in the high impedance, OFF state when at least one of the following conditions occur: the resistance between the power and ground outputs is less than a threshold resistance, and current drawn by the current controller through the power input exceeds a threshold current level.

Abstract: An apparatus and method for controlling a power supply which is coupled to an integrated circuit (IC) that is subject to latch-up is provided. The apparatus includes a comparator circuit that compares a voltage across the IC with a threshold and provides a comparator output. A restart circuit that receives the comparator output, and that receives a fault status signal from the power supply is also included. The restart circuit initiates a restart by shutting off the power supply if the fault status signal is indicative of a latch-up condition in the IC. The restart circuit turns on the power supply if the comparator output indicates that the voltage across the IC is below the threshold.

Abstract: A power booster circuit for use with an integrated circuit coupled to power supply circuitry. The integrated circuit includes a first circuit block that operates at a first voltage level and a second circuit block that operates at a second voltage level. The power supply circuitry includes a first regulator that receives a main supply voltage and provides a first supply voltage at the first level and a second regulator that receives the first supply voltage and provides a second supply voltage at the voltage level. The power booster circuit provides a temporary supply voltage at a third level to the second circuit block in response to the main supply voltage during a time interval between a first time at which the first supply voltage reaches the first level and a second time at which the second supply voltage reaches the second level upon power up of the integrated circuit.

Abstract: An inrush current controller for a device has a connector for hot-plugging the device into a source of energization. An impedance has a current input coupled to a first contact of the connector and a current output coupled to the device. The impedance has an impedance control input. An impedance control circuit has a logic input coupling to a second contact of the connector. The impedance control circuit has an impedance control output connected to the impedance control input. The impedance control output forces the impedance OFF during a first time interval after hot-plugging. The logic input triggers a limited inrush at the current input after the first time interval.

Abstract: A disc drive includes a disc mounted to a rotatable spindle, a motor coupled to the spindle, and motor control circuitry. The motor has a motoring mode in which it rotates the spindle and a braking mode in which is decelerates the rotating spindle and generates power. The motor control circuitry is adapted to control the modes of the motor. The disc drive also includes an auxiliary power output that is generated while operating the motor in the braking mode. The auxiliary power output is made accessible to electronic components that are collateral to the disc drive.

Abstract: Method and apparatus for operating a motor. During a commutation state current is applied to a motor while field effect transistors (FETs) are held in an enable or disable state to effect current in phases of the motor. The phases have a high FET and a low FET. Control circuitry is employed to detect back electromotive force and zero crossing (Zc) signals that indicate transition timing for the commutation states. At a transition state the current is decreased in accordance with a noninstaneous decay function and applying a pulse width modulated signal to a switching element. Alternatively, the current is decreased by enabling either all low side FETs or all high side FETs to allow the current to decay. The next commutation state is applied after the current has been reduced, avoiding negative current to be source from ground and reducing current spikes in the motor.

Abstract: A regulator provides a load voltage. The regulator includes a power driver having a feedback input and a power driver voltage. The regulator includes a comparator having a comparator output related to a combination of the load voltage and a power driver current. The regulator includes a pulse generator controlled by the comparator output and having output pulses with fixed pulse widths. The regulator includes a time limit circuit controlled by the output pulses. The time limit circuit provides the output pulses to the feedback input subject to a time limit between the output pulses.

Abstract: A regulator provides a load voltage. The regulator includes a power driver having a feedback input and a power driver voltage. The regulator includes a comparator having a comparator output related to a combination of the load voltage and a power driver current. The regulator includes a pulse generator controlled by the comparator output and having output pulses with fixed pulse widths. The regulator includes a time limit circuit controlled by the output pulses. The time limit circuit provides the output pulses to the feedback input subject to a time limit between the output pulses.

Abstract: An apparatus and associated method used to control a disc drive having at least one disc and a transducer positionable relative to the disc by a motor. The motor receives energization through at least one power switch integrated on a semiconductor circuit. Temperature of the circuit is sensed proximate the power switch. A temperature signal is provided which is indicative of whether the sensed temperature meets one of a plurality of different threshold temperatures. The power switch is controlled in one of a plurality of different control modes based upon the temperature signal.

Abstract: A power booster circuit for use with an integrated circuit coupled to power supply circuitry is provided. The integrated circuit includes a first circuit block that operates at a first voltage level and a second circuit block that operates at a second voltage level. The power supply circuitry includes a first regulator that receives a main supply voltage and provides a first supply voltage at the first voltage level and a second regulator that receives the first supply voltage from the first regulator and provides a second supply voltage at the second voltage level. The power booster circuit provides a temporary supply voltage at a third voltage level to the second circuit block in response to the main supply voltage during a time interval between a first time at which the first supply voltage reaches the first voltage level and a second time at which the second supply voltage reaches the second voltage level upon power up of the integrated circuit.

Abstract: A disc drive includes a disc mounted to a rotatable spindle, a motor coupled to the spindle, and motor control circuitry. The motor has a motoring mode in which it rotates the spindle and a braking mode in which is decelerates the rotating spindle and generates power. The motor control circuitry is adapted to control the modes of the motor. The disc drive also includes an auxiliary power output that is generated while operating the motor in the braking mode. The auxiliary power output is made accessible to electronic components that are collateral to the disc drive.

Abstract: Method and apparatus for operating a motor. During a commutation state current is applied to a motor while field effect transistors (FETs) are held in an enable or disable state to effect current in phases of the motor. The phases have a high FET and a low FET. Control circuitry is employed to detect back electromotive force and zero crossing (Zc) signals that indicate transition timing for the commutation states. At a transition state the current is decreased in accordance with a noninstaneous decay function and applying a pulse width modulated signal to a switching element. Alternatively, the current is decreased by enabling either all low side FETs or all high side FETs to allow the current to decay. The next commutation state is applied after the current has been reduced, avoiding negative current to be source from ground and reducing current spikes in the motor.

Abstract: A motor control circuit which applies current to a multiphase spindle motor. The spindle motor comprises a plurality of phases and preferably supports a data storage disc of a data storage device. The motor control circuit comprises a sense resistor connected to the voltage source, a plurality of upper switching elements each connected in series between the sense resistor and a different one of the phases of the spindle motor, and a plurality of lower switching elements each connected in series between a different one of the phases of the spindle motor and a reference terminal having a second potential lower than the first potential. A driver circuit selectively applies control signals to the switching elements to apply the desired magnitude of current from the voltage source, through the sense resistor and to the spindle motor.

Abstract: An apparatus and associated method used to control a disc drive having at least one disc and a transducer positionable relative to the disc by a motor. The motor receives energization through at least one power switch integrated on a semiconductor circuit. Temperature of the circuit is sensed proximate the power switch. A temperature signal is provided which is indicative of whether the sensed temperature meets one of a plurality of different threshold temperatures. The power switch is controlled in one of a plurality of different control modes based upon the temperature signal.

Abstract: A disk drive is connectable to a power supply having a fixed DC voltage. The disk drive includes a voice coil motor and a spindle motor. A DC to DC voltage converter converts the fixed DC voltage to an increased DC voltage greater than the fixed DC voltage. A voice coil motor driver has switching elements which are controllable to supply the increased DC voltage to the voice coil motor. A spindle motor driver has switching elements which are controllable to supply the increased DC voltage to the spindle motor. The increased VCM voltage allows faster access times and more efficient VCM operation. The increased spindle motor voltage allows for more efficient spindle motor operation.

Abstract: A disk drive includes a disk having data tracks including servo sectors and data regions disposed between the servo sectors. A transducer head writes data to and reads data from the data regions and reads servo information from the servo sectors. A spindle motor rotates the disk. A spindle motor driver provides current to the spindle motor. A track-following controller is responsive to the servo information for causing the transducer head to remain on track. A microprocessor performs a power-saving idle operation of causing the spindle motor driver to sequentially (1) provide no current to the spindle motor for at least one disk revolution and (2) provide current to the spindle motor for at least one disk revolution. The power-saving idle operation is performed while the track-following controller causes the transducer head to remain on track for multiple disk revolutions.

Abstract: A disk drive includes a voice coil motor (VCM) and a VCM power source circuit which is coupled to a standard power supply having a fixed voltage. During seek operations the VCM power source circuit provides a boosted voltage, greater than the fixed supply voltage, for the VCM. The VCM power source circuit provides the boosted voltage independently from the back EMF generated in the voice coil motor. The increased VCM voltage allows faster access times and more efficient VCM operation.

Abstract: An inrush current controller for a device has a connector for hot-plugging the device into a source of energization. An impedance has a current input coupled to a first contact of the connector and a current output coupled to the device. The impedance has an impedance control input. An impedance control circuit has a logic input coupling to a second contact of the connector. The impedance control circuit has an impedance control output connected to the impedance control input. The impedance control output forces the impedance OFF during a first time interval after hot-plugging. The logic input triggers a limited inrush at the current input after the first time interval.