公开(公告)号：JP2004012463A

公开(公告)日：2004-01-15

申请号：JP2003161170

申请日：2003-06-05

Applicant: ST MICROELECTRONICS INC

Inventor： PEDRAZZINI GIORGIO ,  CERATO SANDRO ,  SALINA ALBERTO

IPC: G01R31/28 ,  H02P6/00

Abstract: PROBLEM TO BE SOLVED: To provide a technology enabling a performance tuning in a multichip electronic system. SOLUTION: In this invention, the multichip system is provided, and at least one chip therein has a coded performance parameter. After integration of the system, the performance parameter is acquired by a companion chip, and can be used for finely adjusting the companion chip automatically or semi-automatically relative to a specific parameter of at least one chip. COPYRIGHT: (C)2004,JPO

公开(公告)号：JP2003164193A

公开(公告)日：2003-06-06

申请号：JP2002302024

申请日：2002-10-16

Applicant: ST MICROELECTRONICS INC

Inventor： PEDRAZZINI GIORGIO ,  FONG HIN SING ,  RAVISHANKER KRISHNAMOORTHY

IPC: H02P25/06 ,  H02P25/02 ,  H02P29/00 ,  H02P7/00

Abstract: PROBLEM TO BE SOLVED: To provide a multi-mode motor controller architecture whose form is easily repetitively changeable so as to be operated in a plurality of operation modes, and which is allowed to be operated relating to a wide-range controller circuit. SOLUTION: The multi-mode motor controller architecture has a motor, an integrated circuit controller, and an integrated-circuit driver circuit. The integrated circuit controller has a pulse generator, DAC, ADC, and a digital compensator circuit. The integrated-circuit-driver circuit is in a communicating state with the controller; and has an error amplifier, a first and second output amplifier to drive the motor, and a sense amplifier. The motor controller architecture is configurable so as to be operated in a linear mode, a pulse mode, or a switchable linear/pulse mode. The controller architecture is, for example, allowed to be obtained with an external compensation circuit of a resistor/ capacitor circuit or the like, or with a digital compensation circuit positioned within the controller integrated circuit. COPYRIGHT: (C)2003,JPO

公开(公告)号：JP2000116181A

公开(公告)日：2000-04-21

申请号：JP23355599

申请日：1999-08-20

Applicant: ST MICROELECTRONICS INC

Inventor： PEDRAZZINI GIORGIO

IPC: G11B21/02 ,  G11B21/08 ,  G11B21/10 ,  G11B21/12 ,  H02P25/06 ,  H02P7/00

Abstract: PROBLEM TO BE SOLVED: To control a voice coil motor with high precision and stability for a long period by giving positive feedback with the first loop gain in a head parking or unparking operation mode, and negative feedback together with the second loop gain in any other operation mode. SOLUTION: In the head parking and head unparking operation mode of a voice coil motor drive circuit 30, a switch 65 responds to a control signal from a control logical connected to a control terminal 69 and gives an opening circuit to between the first and second terminals 67, 68 of the switch 65. The switch 70 responds to the control signal connected to a control terminal 74 from the control logical to give a short circuit to between terminals 72, 74. In any other operation mode, the switch 65 gives a short circuit to between the first and second terminals 67, 68. The switch 70 separates the output terminal 61 of a ramping amplifier 55 from the input terminal 79 of a feedback amplifier 80 to permit the ramping amplifier 55 to be inoperative.

公开(公告)号：JP2001169583A

公开(公告)日：2001-06-22

申请号：JP2000329004

申请日：2000-10-27

Applicant: ST MICROELECTRONICS INC

Inventor： PEDRAZZINI GIORGIO

IPC: G11B21/12 ,  G11B5/54 ,  G11B5/60 ,  G11B21/10 ,  G11B21/22 ,  H02P25/06 ,  H02P5/00 ,  G11B21/02

Abstract: PROBLEM TO BE SOLVED: To provide a technique for improving the control of the speed of read/write heads of a disk-drive device. SOLUTION: This ramp loading method and device controls the application of a drive current to a voice coil in a hard disk drive system. More specifically, a periodical waveform is modulated by either a signal and a reference level related to back electromotive force(BEMF) being stored in the voice coil. The drive current is applied to the voice coil during the time period being modulated by a signal related to the BEMF where the periodical waveform is stored. The amplitude and period of the drive current decrease as BEMF in the voice coil decreases. Therefore, the voice coil is controlled based on the BEMF, and gradually decreasing power is supplied since a head mechanism is moved closer to or away from a ramp assembly body.