Texas Instruments Corporation

Gregory Swize

John Kevin Rote

Wenxiao Tan

Brian Lee Schmidt

Hao Chen

Qunying Li

Mehedi Hassan

Bertram John White

The present invention provides a method for driving a three-phase motor with a driver. The driver can provide a pulse-width modulated driving signal and a linear driving signal. The three-phase motor has a first leg, a second leg and a third leg. The method includes: connecting the second leg to the driver; floating the third leg; driving the second leg with the pulse-width-modulated driving signal from the driver; estimating a time when a voltage in the third leg will reach a predetermined threshold; and driving the second leg with the linear driving signal during that time.

System and method for driving three-phase motor

A high performance digitalized Programmable Gain Amplifier (PGA). In prior art circuit, a dual-ladder DAC is employed for gain control, the back gate leakage of NMOS resistors in the fine ladder conquers fine ladder nominal current and it produces non-monotonic gain scallop. Two new art design techniques: (1) adaptively control the fine ladder; and (2) use dummy PMOS brunch device leakage compensates for the NMOS resistor device leakage, are proposed so that the non-monotonic scallops are substantially eliminated and 13-bit resolution/accuracy PGA has been achieved.

BEMF monitor gain calibration stage in hard disk drive servo integrated circuit

A quiet motor control system is described. This system digitally determines modulated voltages applied to motor phases in a manner that compensates for winding torque distortions, which reduces acoustic emissions.

Quiet motor control system

One embodiment of the invention includes a disk-drive spindle motor power regulator system. The system includes a switching system comprising at least one power transistor for each of a plurality of phases of a disk-drive spindle motor. The system also includes a switching controller configured to generate a plurality of switching signals configured to control the at least one power transistor for each of the plurality of phases of the disk-drive spindle motor. The system further includes a current monitor configured to measure a magnitude of an individual phase current through at least one of the plurality of phases of the disk-drive spindle motor.

Current sensing in a disk-drive spindle motor

A retract circuit () for retracting a data transducer carriage assembly () of a mass data storage device () to a retracted position has a digital state machine () that is user programmable to operate in a selected retract mode. An analog control circuit () is provided for receiving control signals from the digital state machine () for providing analog retract signals to move the data transducer carriage assembly (). The digital state machine () is user programmable to operate in constant voltage, velocity detect, float and pulse, and crash stop detect modes. Preferably, the digital state machine () is programmed to detect a velocity of the data transducer carriage assembly (). The digital state machine () also is preferably programmed to detect an error velocity of the data transducer carriage assembly () from a difference of a measured voltage across the data transducer driver () from a predetermined voltage.

Digital processor controlled method and circuit for retracting a head carriage assembly to a parked position in a mass data storage device, or the like

A hard disk drive energy recovery circuit, a method of recovering energy from a motor of a hard disk drive and a hard disk drive. In one embodiment, the hard disk drive energy recovery circuit includes (1) a spindle resolver that generates transition signals as a spindle motor of the hard disk drive rotates among angular regions, (2) a spindle region state machine, coupled to the spindle resolver, that receives the transition signals and generates rectifier drive signals based thereon and (3) a synchronous rectifier, coupled to the spindle region state machine, that employs the rectifier drive signals to recover electrical energy from the motor.

Efficient hard disk drive energy recovery circuit and method and a hard disk drive incorporating the same

A transconductance circuit ( ) and method for protecting an H-bridge power circuit ( ) that provides power to a load that includes an inductive component ( ) connected between one side of the inductive component ( ) and a gate ( ) of a low side transistor ( ) of the H-bridge ( ). The transconductance circuit ( ) operates to pull current from the inductive component ( ) to ground ( ) when the inductive load ( ) sources current to a body diode of the high side transistor ( ). The transconductance circuit ( ) creates a regulated voltage to the gate ( ) of the low side transistor ( ) to cause the low side transistor ( ) to conduct the current away in a regulated manner from the inductor ( ) and the high side transistor ( ) to ground ( ).

Clamping circuit and method for DMOS drivers

A method of detecting phase error between a phase current and a driving voltage includes generating a signal indicative of the phase current. The method includes identifying a time interval during which the signal indicative of the phase current is generally symmetric about a midpoint of the time interval when the phase error is approximately zero. The method further includes determining the extent to which the signal indicative of the phase current is symmetric about the midpoint of the time interval. Finally, in response to determining the extent to which the signal indicative of the phase current is symmetric, the method includes generating phase error information.

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Dallas, TX, United States of America

Gregory Swize