Texas Instruments Corporation

Frederick W Trafton

John Kevin Rote

Marcus Marchesi Martins

Joao Carlos Brito

Joao Carlos Felicio Brito

Sujanto Gunawan

A configurable voltage regulator () operable in either of two selectable modes or topologies is disclosed. In one disclosed embodiment, the voltage regulator () can operate as a linear regulator or a switching regulator. A gate driver () and an error amplifier () is used in each mode. Configuration switches () are controlled by a configuration amplifier () to connect the error amplifier () to the gate driver () in the linear regulator mode, or to connect the error amplifier () to circuitry () for controlling the gate driver () in switching regulator mode. In another disclosed embodiment, the voltage regulator () generates a negative polarity regulated voltage according to a switching regulator or charge pump topology.

Reconfigurable topology for switching and linear voltage regulators

A method is disclosed for controlling the voltage applied to a voice coil motor coil during the retract operations of a mass storage device, comprising a combination of three different voltage regulator stages. This method includes providing a first circuitry stage adapted to source current to a voice coil motor apparatus, raising the voltage across the voice coil motor to a desired level, providing a second circuitry stage adapted to draw current from the voice coil motor effecting a desired voltage across the voice coil motor, and providing a third circuitry stage adapted to raise the voltage of the voice coil motor to ground by effectively shorting the voice coil motor to ground.

System for voltage regulation of a voice coil motor

An apparatus for controlling an actuator having a moveable member and having a coil that influences movement of the member, by provision of a drive current to the coil in response to a target speed voltage signal. The invention includes an up/down counter, counting at a predetermined count rate and providing a count output. A control unit is provided for controlling the direction of count of the up/down counter depending on whether the voltage across the coil, sensed periodically a first predetermined interval after the drive current to the coil is interrupted, is greater than, or less than, a reference voltage having a predetermined relationship to the target speed voltage. A digital-to-analog converter is provided, responsive to the count output to provide a compensated voltage signal having a voltage corresponding to the count output. A voltage sensing and holding unit is provided that periodically, after the drive current is interrupted for a second predetermined interval, senses and holds a sample voltage corresponding to the voltage across the coil. A plus/minus indicator is provided that senses when the up/down counter is in a down count direction and is at a count of zero, and in response thereto changes between a plus state and a minus state. A switch node is provided, combining the sample voltage signal with the compensated voltage signal to produce a command voltage signal, and providing the command voltage signal with a polarity controlled by the state of the plus/minus indicator. Finally, a transconductance amplifier unit is provided, receiving the command voltage signal and providing the drive current to the coil in a direction determined by the state of the plus/minus indicator.

Growing community of inventors

Lewisville, TX, United States of America

Frederick W Trafton