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公开(公告)号：US12080327B2
公开(公告)日：2024-09-03
申请号：US18354797
申请日：2023-07-19
Applicant: STMicroelectronics S.r.l.
Inventor： Ezio Galbiati , Michele Boscolo Berto , Giuseppe Maiocchi , Maurizio Ricci
Abstract: An embodiment method includes rectifying a back electromotive force of a spindle motor in a hard disk drive and energizing a voice coil motor in the hard disk drive using the rectified back electromotive force of the spindle motor via a voice coil motor power stage to retract a head of the hard disk drive to a park position. The head is retracted by moving the head towards the park position during a first retract phase and retaining the head in the park position during a second retract phase by applying a bias voltage to the voice coil motor power stage during a bias interval of the second retract phase. The method also includes producing a saturation signal indicative of onset of saturation in the voice coil motor power stage and controlling the bias voltage during the second retract phase.
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公开(公告)号：US10749455B2
公开(公告)日：2020-08-18
申请号：US14920042
申请日：2015-10-22
Applicant: STMICROELECTRONICS S.R.L.
Inventor： Michele Boscolo Berto , Ezio Galbiati
Abstract: An ohmic-inductive electrical load, such as an electric motor, for example, for a hard-disk drive, is driven by supplying thereto a load current via a switching power stage supplied with a source current delivered by a supply source. The driving action may include sensing the load current; estimating the source current starting from the load current sensed; generating a feedback signal that assumes different values as a function of the result of the comparison between the source current estimated and a source-current threshold value; and driving the switching power stage via the feedback signal, increasing or decreasing, respectively, as a function of the different values assumed by the feedback signal, the load current, thereby controlling the source current.
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公开(公告)号：US09947350B1
公开(公告)日：2018-04-17
申请号：US15636426
申请日：2017-06-28
Applicant: STMicroelectronics S.R.L.
Inventor： Michele Boscolo Berto , Ezio Galbiati , Giuseppe Maiocchi
IPC: G11B5/55
CPC classification number: G11B5/5534 , G11B5/5547 , G11B5/5565 , H02P6/182 , H02P25/028 , H02P25/034
Abstract: A driver device coupled to a winding of an electro-mechanical actuator includes: a power stage driving the winding in a discontinuous mode by alternating conduction on-phases to off-phases, and a sensor circuit sensing a voltage across the winding in an off-phase, wherein, during such an off-phase the voltage across the winding includes a residual voltage which decays to zero. The power stage drives the winding from an on-phase to an off-phase by applying to the winding a reverse current pulse to invert the direction of flow of the current through the winding and produce an oscillation of the residual voltage, whereby the residual voltage includes a zero-crossing point after the current through the winding is exhausted. The sensor circuit senses the voltage across the winding at this zero-crossing point, whereby the voltage sensed across the winding at the zero-crossing point is indicative of the back electromotive force of the winding.
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4.发明公开公开(公告)号：US20240096371A1
公开(公告)日：2024-03-21
申请号：US18446823
申请日：2023-08-09
Applicant: STMicroelectronics S.r.l.
Inventor： Ezio Galbiati
Abstract: A back electromotive force (BEMF) of a spindle motor in a hard disk drive is rectified and exploited to drive a voice coil motor (VCM) in the hard disk drive to retract the heads of the hard disk drive to a park position. The VCM is driven in a discontinuous mode comprising an alternation of VCM on-times and VCM off-times. Rectifying the BEMF of the spindle motor is discontinued before the end of the VCM off-times, Toff with the spindle motor brought into a brake condition wherein the spindle motor is short-circuited and the spindle BEMF forces currents through the windings of the spindle motor. The spindle current is thus pre-charged and made ready to cope with a VCM current request at the next VCM on-time.
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公开(公告)号：US10892740B2
公开(公告)日：2021-01-12
申请号：US16240915
申请日：2019-01-07
Applicant: STMicroelectronics S.r.l.
Inventor： Giuseppe Maiocchi , Ezio Galbiati , Michele Boscolo Berto
Abstract: A method includes receiving an input digital signal and applying the input digital signal to digital filter processing with a corner frequency to produce a filtered output digital signal. The digital filter processing includes a set of multiplication operations using a set of filter multiplication coefficients. The set of multiplication operations is performed by alternately using a first set of approximate multiplication coefficients and a second set of approximate multiplication coefficients different from the first set of approximate multiplication coefficients. The approximate multiplication coefficients in the first set of approximate multiplication coefficients and the second set of approximate multiplication coefficients approximate multiplication coefficients in the set of filter multiplication coefficients as a function of negative power-of-two values. The alternating of multiplication operations results in digital filter processing with average corner frequency approximating the corner frequency.
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Patent Agency Ranking
公开(公告)号：US20190245521A1
公开(公告)日：2019-08-08
申请号：US16240915
申请日：2019-01-07
Applicant: STMicroelectronics S.r.l.
Inventor： Giuseppe Maiocchi , Ezio Galbiati , Michele Boscolo Berto
CPC classification number: H03H17/0227 , G06F7/523 , H03H17/0225 , H03H17/0248 , H03H17/04 , H03H2017/022
Abstract: A method includes receiving an input digital signal and applying the input digital signal to digital filter processing with a corner frequency to produce a filtered output digital signal. The digital filter processing includes a set of multiplication operations using a set of filter multiplication coefficients. The set of multiplication operations is performed by alternately using a first set of approximate multiplication coefficients and a second set of approximate multiplication coefficients different from the first set of approximate multiplication coefficients. The approximate multiplication coefficients in the first set of approximate multiplication coefficients and the second set of approximate multiplication coefficients approximate multiplication coefficients in the set of filter multiplication coefficients as a function of negative power-of-two values. The alternating of multiplication operations results in digital filter processing with average corner frequency approximating the corner frequency.
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公开(公告)号：US12190909B2
公开(公告)日：2025-01-07
申请号：US18300806
申请日：2023-04-14
Applicant: STMicroelectronics S.r.l.
Inventor： Ezio Galbiati , Maurizio Ricci
IPC: G11B19/20
Abstract: A method includes coupling an electric motor in a hard disk drive to a set of driver circuits. Each driver circuit includes a high-side switch and a low-side switch. The high-side switch has a high-side current flow path between a supply node coupled to a supply voltage and a switching node coupled to a winding of the electric motor. The low-side switch has a low-side current flow path between the switching node and ground. Respective conduction currents are generated through the low-side current flow paths, in response to a command to reduce the motor speed by coupling a drive voltage to the control terminals of the low-side switches. An intensity of at least one of the respective conduction currents is sensed. In response to the sensed current intensity exceeding a current intensity threshold, the control terminals of the low-side switches are coupled to respective ones of the switching nodes.
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公开(公告)号：US12119024B2
公开(公告)日：2024-10-15
申请号：US18446823
申请日：2023-08-09
Applicant: STMicroelectronics S.r.l.
Inventor： Ezio Galbiati
Abstract: A back electromotive force (BEMF) of a spindle motor in a hard disk drive is rectified and exploited to drive a voice coil motor (VCM) in the hard disk drive to retract the heads of the hard disk drive to a park position. The VCM is driven in a discontinuous mode comprising an alternation of VCM on-times and VCM off-times. Rectifying the BEMF of the spindle motor is discontinued before the end of the VCM off-times, Toff with the spindle motor brought into a brake condition wherein the spindle motor is short-circuited and the spindle BEMF forces currents through the windings of the spindle motor. The spindle current is thus pre-charged and made ready to cope with a VCM current request at the next VCM on-time.
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公开(公告)号：US20240038268A1
公开(公告)日：2024-02-01
申请号：US18343868
申请日：2023-06-29
Applicant: STMicroelectronics S.r.l.
Inventor： Ezio Galbiati
CPC classification number: G11B21/025 , G11B25/043 , G11B27/36 , G11B2220/2516
Abstract: A circuit includes a set of input nodes configured to be coupled to respective ones of the windings of a spindle motor in a hard disk drive to sense the voltages applied to the windings. A set of output nodes is configured to provide output signals indicative of direction of flow of the currents through the windings. Level shifters are coupled to respective input nodes in the set of input nodes and have level-shifted output nodes configured to provide down-shifted replicas of the voltages at the respective input nodes in the set of input nodes. Flip-flops have inputs coupled to respective ones of the level-shifted output nodes of the level shifters and outputs configured to provide the output signals coupled to respective output nodes.
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10.发明公开公开(公告)号：US20230318493A1
公开(公告)日：2023-10-05
申请号：US18176778
申请日：2023-03-01
Applicant: STMicroelectronics S.r.l.
Inventor： Ezio Galbiati
Abstract: In accordance with an embodiment a method includes: receiving a slow down command to slow down a speed of a voice coil motor (VCM) in a hard disk drive; in response to receiving the slow down command, operating the VCM in a discontinuous mode by switching on and off a current through the VCM with a duty-cycle, wherein operating the VCM in the discontinuous mode reduces the speed of the VCM; sensing the speed of the VCM while operating the VCM in the discontinuous mode; and varying the duty-cycle of the switching on and off the current through the VCM as a function of the sensed speed of the VCM operated in the discontinuous mode, wherein varying the duty-cycle comprises reducing the duty-cycle in response to a reduction of the sensed VCM speed.
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