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公开(公告)号:JP2001101609A
公开(公告)日:2001-04-13
申请号:JP2000275203
申请日:2000-09-11
Applicant: ST MICROELECTRONICS INC
Inventor: PATTI GUISEPPE , ALINI ROBERTO , PAKRISWAMY ELANGO
Abstract: PROBLEM TO BE SOLVED: To provide an improved circuit and the method for driving a writing head of a disk storage device. SOLUTION: When the current flowing direction through the writing head is inverted from the 1st direction supplying the current to the writing head through a writing head terminal to the 2nd direction drawing out the current from the writing head through the writing head terminal, a bootstrap circuit and a current sync circuit are activated to enable the current to be quickly drawn out from the writing head.
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公开(公告)号:JP2000163705A
公开(公告)日:2000-06-16
申请号:JP32907799
申请日:1999-11-19
Applicant: ST MICROELECTRONICS INC
Inventor: PATTI GUISEPPE , LEE EUGENE C , ALINI ROBERTO
Abstract: PROBLEM TO BE SOLVED: To remove the ringing and unnecessary offset of a read signal by making resistance values equal to a 1st and a 2nd specific resistance value in response to a 1st and a 2nd control input and generating the 2nd control input in response to the detection of a thermal event. SOLUTION: An effective resistance value is given by a resistance R1 and the programmed resistance value of a resistance R1 and a variable resistance value circuit 132 and the cutoff frequency of a filter 112 varies as the resistance value of the variable resistance value circuit 132 varies. In a normal operation period of a read channel, the resistance value of the variable resistance value circuit 132 is relatively high impedance and the effective resistance value of the filter 112 becomes substantially equal to the resistance value of the resistance R1. When thermal variation is detected, the effective resistance value of the filter 112 decreases to increase the cutoff frequency. This effective resistance value decreases by programming the variable resistance value circuit 132 to a specific resistance value in response to the input signal from a control circuit 110.
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公开(公告)号:JP2003187402A
公开(公告)日:2003-07-04
申请号:JP2002327083
申请日:2002-11-11
Applicant: ST MICROELECTRONICS INC
Inventor: VENCA ALESANDRO , POSAT BARIS , OZANOGLU KEMAL , ALINI ROBERTO
Abstract: PROBLEM TO BE SOLVED: To provide a circuit and a method which comparatively rapidly transition a current flowing through a write head during normal operating conditions, without generating capacitively coupled noise. SOLUTION: A drive voltage signal which will not have a common mode voltage level in a transition period among the normal operating conditions in the write head is supplied to the write head. That is, the drive voltage signal impressed to the writing head is substantially and entirely differential during the transition period of a write head current. A driver circuit has the terminal of the write head and a switching circuit, connected between reference voltage supply sources such as positive and negative voltage sources. The driver circuit has a timing circuit for generating a controlling signal which controls the switching circuit. COPYRIGHT: (C)2003,JPO
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公开(公告)号:JP2002123902A
公开(公告)日:2002-04-26
申请号:JP2001260774
申请日:2001-08-30
Applicant: ST MICROELECTRONICS INC
Inventor: PATTI GUISEPPE , ALINI ROBERTO
Abstract: PROBLEM TO BE SOLVED: To provide an improved method and the circuit for controlling a write head for a magnetic disk storage device. SOLUTION: When the flow direction of the current is reversed from the 1st direction in which the current is being supplied to the write head through a write head terminal to the 2nd direction in which the current is drawn out from the write head through the write head terminal, an appropriate pull-up device is activated during the period of specified time. A clamp device being connected to the pull-up device to be temporarily activated is activated after that, thereby the corresponding write head terminal is clamped to the intermediate voltage level at the steady state.
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公开(公告)号:JP2002123903A
公开(公告)日:2002-04-26
申请号:JP2001261663
申请日:2001-08-30
Applicant: ST MICROELECTRONICS INC
Inventor: ALINI ROBERTO , LAM QUOCDZUNG T , CHEW XIAOKUN LIU , MACCORNACK MARK , BEZINQUE DAVID JOSEPH , LEE TEHRI , LE SU DANG , AXEL ALLEGRET DE LA SJORLES , DENOYER GILLES
Abstract: PROBLEM TO BE SOLVED: To provide an improved method for controlling a writing head of a magnetic disk recorder. SOLUTION: In this method, the current is sunk from a 1st terminal of the writing head and also the current is substantially and simultaneously supplied to a 2nd terminal of the writing head, and consequently the voltage level of 1st normal state is presented on the 1st terminal of the writing head and the voltage level of 2nd normal state is presented on the 2nd terminal of the writing head, and these levels show the nearly middle points between the high reference voltage level and low reference voltage level. The common mode voltage of the writing head is substantially constant as to the time, accordingly.
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公开(公告)号:DE69427479T2
公开(公告)日:2002-01-17
申请号:DE69427479
申请日:1994-11-30
Applicant: ST MICROELECTRONICS SRL
Inventor: BRIANTI FRANCESCO , PISATI VALERIO , ALINI ROBERTO , MOLONEY DAVID
IPC: G05F3/26
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公开(公告)号:DE69231151D1
公开(公告)日:2000-07-13
申请号:DE69231151
申请日:1992-08-26
Applicant: ST MICROELECTRONICS SRL
Inventor: CASTELLO RINALDO , ALINI ROBERTO , REZZI FRANCESCO , PISATI VALERIO
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公开(公告)号:DE69327053D1
公开(公告)日:1999-12-23
申请号:DE69327053
申请日:1993-09-21
Applicant: ST MICROELECTRONICS SRL
Inventor: MOLONEY DAVID , GADDUCCI PAOLO , BETTI GIORGIO , ALINI ROBERTO
Abstract: In a decoder for decoding a serial data stream, employing an extracted base clock signal, synchronous with an input, coded, serial data stream, a fractionary frequency clock signal for sampling a decoded output data stream and a second fractionary clock signal for synthesizing a pre-decoded value produced by a first combinative logic network within a second combinative logic network to produce a decoded value that is sent to an output sampling flip-flop, a pipelined operation is implemented by momentarily storing the bits that are processed in the second combinative logic network and by anticipating of two full cycles of the synchronous base clock the processing by said first combinative network of the n-number of bits handled by the decoder. Each one of the two combinative logic networks is permitted to complete its decoding process within a full clock cycle in advance of the raising front of the outpunt sampling clock signal. With the same fabrication technology and therefore with the same propagation delay of the two combinative logic networks, the maximum operating spead may be doubled. A limited number of additional components are required to implement the pipelined operation of the invention.
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公开(公告)号:DE69427471T2
公开(公告)日:2002-04-25
申请号:DE69427471
申请日:1994-07-29
Applicant: ST MICROELECTRONICS SRL
Inventor: PISATI VALERIO , ALINI ROBERTO , CASTELLO RINALDO , VAI GIANFRANCO
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公开(公告)号:DE69427471D1
公开(公告)日:2001-07-19
申请号:DE69427471
申请日:1994-07-29
Applicant: ST MICROELECTRONICS SRL
Inventor: PISATI VALERIO , ALINI ROBERTO , CASTELLO RINALDO , VAI GIANFRANCO
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