Sgs-thomson Microelectronics S.r.l.

Sgs-thomson Microelectronics Limited

Nippon Densan Corporation

Sandro Cerato

Francesco Carobolante

Angelo Alzati

Isao Kaneda

Carlo C De Martiis

Antonella Baiocchi

Kohei Yonemura

The invention is used in a disk drive and comprises a feedforward circuit connected between the head position circuit and the speed control loop circuit. The feedforward circuit precompensates the speed control loop for changes in rotation drag due to movements in the head of a disk drive. The feedforward circuit may include one or more deadband amplifiers and may include filter circuit. The invention disclose the method for controlling the speed of a spindle motor in a disk drive which includes the step of precompensating the speed control loop circuit with a processed head positioning signal.

Feedforward circuit and method for controlling the speed of a spindle

A DC motor having a housing, a hub member rotatably supported by the housing, a flexible printed circuit board fixedly mounted on the housing, and an IC chip mounted on the flexible printed circuit board and located facing a recess formed in the housing. The hub member has a shaft rotatably supported by a bearing within the recess. The flexible printed circuit board has a metal layer for mounting the IC chip, the metal layer being isolated from a wiring pattern formed on the printed circuit board. The wiring pattern on the flexible printed circuit board is directly connected to a connection pin connected to the motor wiring.

IC controlled DC motor

A circuit device, made up of a reduced number of components, for simultaneously turning on a plurality of power transistors, being of a type adapted to be connected between the output of an oscillator and the bootstrap input of a turn-on circuit which are both incorporated into an integrated circuit also incorporating said transistors, further comprises:

Circuit device, made up of a reduced number of components, for

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Sandro Cerato