Texas Instruments Corporation

Silergy Corp.

Maxim Integrated Products, Inc.

Siliconsystems, Inc.

Silergy Semiconductor (hong Kong) Limited

Bertram John White

Tanchu Shih

Hao Chen

John Kevin Rote

Gregory Swize

Kevin William Ziemer

Charles C Austin

Vincent T Ng

Nathan Theodore Hackett

Michael Arkin

Ying Zhang McCleary

A differential coupling path is provided for power measurement communication between a host device and a line side device. The line side device couples to AC power grid to extract voltage signals and current signals using various voltage and current sensors. The extracted voltage signal and current signal are converted to digital signals by internal A/D converters within the line device and then sent to the host device through the differential coupling path coupled between the host device and the line side device. The host device may couple to one or more line side devices via multiple differential coupling paths.

Method of communicating between phases of an AC power system

Various embodiments of the invention relate generally to real-time clock circuit, and more particularly to systems, devices and methods of integrating two oscillators in one real-time clock circuit to generate accurate time of day over an industrial temperature range. A primary oscillator is employed to generate a first high precision clock while having a higher frequency and consuming more power; a secondary oscillator is employed to generate a second clock that has a low frequency and consumes less power, but may not meet the time accuracy requirement. When the real-time clock is provided with sufficient power (MSN mode), time of day is constantly tracked by the primary oscillator, but when the real-time clock is powered by a battery (SLEEP mode), time of day is tracked by the secondary oscillator while the primary oscillator is switched on at an update frequency to compensate errors in the time of day.

Apparatus and method of keeping time of day over an industrial temperature range

A system and method of motor control enable improved motor control by controlling a phase winding to float or enter a high impedance state prior to activating phase detection of the phase winding. Because the phase winding floats prior to phase detection, the effect residual current coupling in such phase can be mitigated and thereby help improve motor operation.

System and method for improved motor control

A spindle motor control circuit for controlling a motor; including a control circuit to control the motor during at least a low state, a pulse state and a high state, the motor braking during said low state, the control circuit receiving a flyback voltage from the motor during the pulse state and the control circuit receiving a reduced flyback voltage from the motor during the high state.

Disk drive servo arm retract and spindle brake circuit

A lead frame for an integrated circuit includes a ground for the integrated circuit to ground the integrated circuit, the lead frame having at least one corner connected to the ground; and a connector between the corner of the lead frame and the ground located on the integrated circuit.

Corner bonding to lead frame

The present invention includes a charge pump circuit to raise a voltage including a voltage source to generate the voltage to be raised, a pair of switches to switch the voltage to a capacitor with the first pair of switches operating during different periods of time and a second pair of switches to switch additional voltage to the capacitor with the second pair of switches operating during different periods of time.

Low slew rate charge pump

The present invention includes a circuit to maintain a constant voltage on a storage element such as a capacitor at the output of a regulator during an emergency power condition. It includes a detector to detect the emergency condition and to generate a fault signal in response to the emergency condition, a one-shot time delay circuit to delay the enabling of a regulator in response to the fault signal, and a second delay unit to delay the enabling of the load of a regulator to accommodate the non-zero recovery time of a regulator. These two time delay units are able to bypass the noisy switching on the fault signal so that the maintained voltage on the storage capacitor will not droop and can be reliably used for such purposes as head retract and spindle brake under a noisy power emergency situation.

Method for preserving charges on a cap at the output of a regulator

A circuit for providing commutation control signals to a commutator for a polyphase brushless dc motor in a mass data storage device includes an accumulator ( ) to accumulate a digital count that is proportional or related to a phase difference between the commutation control signals and a motor bemf. A digital variable frequency oscillator ( ) generates an oscillator output signal of frequency proportional to the digital count to reset the accumulator ( ) after a predetermined time determined by the frequency. The circuit may also include a digital filter ( ) between the digital accumulator ( ) and the digital variable frequency oscillator ( ) to generate a magnitude signal (DRC) of magnitude proportional to the accumulated count for delivery to the variable frequency oscillator ( ) to control the frequency thereof.

Digital PLL filter and VCO for use in controlling a spindle motor of a mass data storage device

A method and circuit for operating a polyphase dc motor in which discontinuous sinusoidal drive voltages are applied to the windings of the motor in predetermined phases. The discontinuous portion of the sinusoid is timed with the bemf zero crossings. Bemf zero crossings are detected, and phases of the drive voltages are adjusted to have zero crossings substantially in the discontinuities of the drive voltages. The method and circuit result in motor operation with significantly reduced acoustic motor noise.

Method and apparatus for synchronizing PWM sinusoidal drive to a DC motor

A method and circuit are presented for operating a polyphase dc motor in which substantially sinusoidal drive voltages are applied to the windings of the motor in predetermined phases. Zero crossings of currents flowing in respective windings of the motor are detected, and phases of the drive voltages are adjusted to have zero crossings substantially simultaneously with the detected zero crossings of the currents flowing in respective windings of the motor. The method and circuit results in motor operation with significantly reduced acoustic motor noise.

Method and apparatus for driving a polyphase, brushless DC motor

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.

Method and apparatus for controlling a motor in a mass storage device

A circuit to provide adaptive commutation delay for multi-pole brushless DC motors. The circuit adjusts the commutation delay as a function of the rotational speed of the motor to maximize motor torque and minimize power consumption. Unlike the prior art, the circuit avoids the need for complex circuitry or external components. The circuit may be implemented entirely within a single integrated circuit. The circuit includes a back-EMF sensing input, an oscillator, a voltage holding and proportioning circuit, one or more comparators and, optionally, an external control circuit. The back-EMF sensing input controls the operation of the oscillator. The voltage holding and proportioning circuit processes the oscillator output and provides outputs which are compared by the comparators. The comparators produce commutation delay signals and, optionally, other signals. The circuit also allows adjustment to compensate for non-ideal back-EMF-to-rotor-position correspondence or fixed time delays inherent in the commutation process.

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Irvine, CA, United States of America

Bertram John White