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AssigneeSTMicroelectronics S.r.l.
InventorsMassimiliano Brambilla, Maurizio Nessi, Ezio Galbiati
Estimating the term…
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.
A control circuit providing a driving current to a voice coil motor to position a reading and writing head of a disk memory system, said circuit comprising a first and a second class AB amplifiers the outputs of which are connected to the terminals of a first resistor in series with said voice coil motor so that a current passes through said voice coil motor and through said first resistor, said circuit comprising 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 a signal present which is a sum of an external signal and of an output signal of the sense amplifier, said first amplifier and said second amplifier being driven in inverted phase by an output signal produced by said device, comprising 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 when said circuit operates in a track-follow mode and so that said sense amplifier has the input terminals coupled with the terminals of said series of resistors.
Dependencies are inferred from the claim text.