公开(公告)号：DE69719317D1

公开(公告)日：2003-04-03

申请号：DE69719317

申请日：1997-07-17

Applicant: ST MICROELECTRONICS SRL

Inventor： MAIOCCHI GIUSEPPE ,  GALBIATI EZIO

IPC: H02M7/5387 ,  H02P6/08 ,  H02P7/06 ,  H03M1/82

Abstract: The definition of conversion of a digital value in a PWM signal using an N-bit up/down counter is improved by increasing the dimension of the input datum to N+2 bits, using the two lsb of the N+2 input datum for selecting one among three intermediate levels between two consecutive values of an N-bit dynamic, according to a predefined table of combinations. The converter may still use an N-bit comparator.

公开(公告)号：DE69523752T2

公开(公告)日：2002-08-29

申请号：DE69523752

申请日：1995-08-31

Applicant: ST MICROELECTRONICS SRL

Inventor： GALBIATI EZIO

IPC: H02P7/29 ,  H02M7/5387 ,  H02P7/00

公开(公告)号：DE69523752D1

公开(公告)日：2001-12-13

申请号：DE69523752

申请日：1995-08-31

Applicant: ST MICROELECTRONICS SRL

Inventor： GALBIATI EZIO

IPC: H02P7/29 ,  H02M7/5387 ,  H02P7/00

公开(公告)号：ITMI20002176D0

公开(公告)日：2000-10-09

申请号：ITMI20002176

申请日：2000-10-09

Applicant: ST MICROELECTRONICS SRL

Inventor： BRAMBILLA MASSIMILIANO ,  NESSI MAURIZIO ,  GALBIATI EZIO

IPC: G11B21/08 ,  G11B21/10 ,  H02P25/06 ,  H03F3/187 ,  H03F3/30

Abstract: A control circuit providing a driving current to a voice coil motor to position a reading and writing head of a disk memory system is described. The circuit comprises a first and a second class AB amplifiers the outputs of which are connected to the terminals of a first resistor in series with the voice coil motor so that a current passes through the voice coil motor and through the first resistor. The circuit comprises a sense amplifier the input terminals of which are coupled with the terminals of said first resistor, a device at the input of which is present a signal which is a sum of an external signal and of an output signal of the sense amplifier. The first amplifier and the second amplifier being driven in inverted phase by an output signal produced by the device. The circuit comprises means for inserting a second resistor in series with the first resistor so that said current passes through the series of said first and said second resistors and so that said sense amplifier has the input terminals coupled with the terminals of said series of resistors.