Texas Instruments Corporation

Joao Carlos Felicio Brito

Qunying Li

Juergen Luebbe

John Kevin Rote

Hector Torres

Wenxiao Tan

Dongjie Cheng

Frederick W Trafton

Javier Antonio Valle Mayorga

A hermetic ceramic package for high current signals includes a substrate made of a plurality of ceramic green sheets that form an upper body portion having an upper surface and a lower body portion having a lower surface and an intermediate surface between the upper surface and the lower surface. A first conductive plate is formed on the intermediate surface and a first plurality of conductive pad vias are formed in the lower body portion, extending from the first conductive plate to the lower surface of the lower body portion. A heat sink if coupled to the lower surface of the lower body portion and a first conductive pad also coupled to the lower surface such that the first conductive pad is electrically coupled to the first plurality of conductive pad vias.

Ceramic package opening, heat sink, vias coupled to conductive pad

Methods and apparatus providing a smooth transition from a pulse width modulation mode to a linear mode to drive a voice coil motor are disclosed. An example apparatus includes an H-bridge; a pulse generator to generate a pulse when the voice coil motor driver transitions from pulse width modulation mode to linear mode; a first boost circuit to, when the pulse is generated, increase a first current being applied to a first gate of a first transistor in the H-bridge, the increase in the first current enabling the first transistor; and a second boost circuit to, when the pulse is generated, provide an additional path to ground from a node coupled to a second gate of a second transistor of the H bridge, the path to ground corresponding to a voltage drop that disables the second transistor.

Voice coil motor pulse width modulation-to-linear smooth transition control

One embodiment includes a back-electromagnetic force (BEMF) sense system. The system includes a sense amplifier configured to measure an amplitude of a selected one of a plurality of phase voltages relative to a center tap voltage associated with a servo motor for the calculation of an associated BEMF voltage. The plurality of phase voltages can be provided to the sense amplifier via a respective plurality of control nodes. The selected one of the plurality of phase voltages on a respective one of the control nodes can be selected based on coupling the other of the plurality of control nodes associated with the other of the plurality of phase voltages to a voltage source configured to provide a predetermined voltage magnitude.

Back electromagnetic force (BEMF) sense system

One embodiment of the invention includes a hysteretic power regulator system. The system includes a switching stage configured to periodically couple an input voltage to an inductor in response to a control signal to generate an output voltage. The system also includes a hysteretic control stage configured to generate the control signal based on a comparison of a feedback voltage associated with the output voltage and a predetermined reference voltage. The system also includes a feed-forward stage configured to generate a feed-forward ramp voltage in response to the control signal. The feed-forward ramp voltage can be added to the feedback voltage to set a frequency of the control signal. The system further includes a compensation stage configured to cancel a DC error associated with the feed-forward ramp voltage relative to the feedback voltage to substantially mitigate errors associated with the output voltage.

Feed-forward compensation for a hysteretic switching regulator

A controller providing increased control with lesser final error for an actuator when there is a force accelerating the actuator, such as at the end of travel during a retract operation. An extension of the integrator may be provided for implementing a second direction to integrate a final error. One embodiment of the invention may comprise a counter and an analog multiplexer controlling the attenuation of the command voltage.

Dual direction integrator for constant velocity control for an actuator using sampled back EMF control

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.

Growing community of inventors

Murphy, TX, United States of America

Joao Carlos Felicio Brito