Abstract: A disk drive data storage system. The system comprises a data storage disk, a movable member positioned near the data storage disk, and a sensor assembly, supported and movable by the movable member, for writing data to and reading data from the data storage disk. The system also comprises an integrated circuit that is electrically coupled to the sensor assembly and that moves with the movable member when the movable member moves the sensor assembly. The integrated circuit comprises a face and a backside, and the integrated circuit is in a fixed physical position relative to the movable member such that the backside is oriented toward the movable member.

Abstract: A disk drive data storage system. The system comprises a data storage disk, a movable member positioned near the data storage disk, and a sensor assembly, supported and movable by the movable member, for writing data to and reading data from the data storage disk. The system also comprises an integrated circuit that is electrically coupled to the sensor assembly and that moves with the movable member when the movable member moves the sensor assembly. The integrated circuit comprises a face and a backside, and the integrated circuit is in a fixed physical position relative to the movable member such that the backside is oriented toward the movable member.

Abstract: A system and method for selecting between two biasing modes for biasing magneto resistive heads in a disk drive. A mode selector selects either a voltage biasing circuit or a current biasing to supply the bias voltage or bias current, respectively, to a magneto resistive head. The selection can be based on changes in parameters in the disk drive or magneto resistive heads during disk drive operation.

Abstract: A method is disclosed for controlling the write head of a magnetic disk storage device. The method includes sinking current from the first terminal of the write head and sourcing current to the second terminal of the write head substantially simultaneously with sinking current from the first terminal so that a first steady state voltage level appears on the first terminal of the write head and a second steady state voltage level appears on the second terminal thereof that are approximately at a midpoint between a high reference voltage level and a low reference voltage level. The common mode voltage of the write head is substantially constant over time.

Abstract: A write head is described having a switchable damping resistance coupled in parallel with an inductor. The damping resistance is decoupled from the inductor by rendering a transistor nonconductive when a direction of current in the inductor changes. The damping resistance is then coupled to the inductor before oscillations begin in the current in the inductor. The decoupling of the damping resistor eliminates power dissipation in the damping resistor during a change in the direction of current in the inductor.

Abstract: A write head is described having a switchable damping resistance coupled in parallel with an inductor. The damping resistance is decoupled from the inductor by rendering a transistor nonconductive when a direction of current in the inductor changes. The damping resistance is then coupled to the inductor before oscillations begin in the current in the inductor. The decoupling of the damping resistor eliminates power dissipation in the damping resistor during a change in the direction of current in the inductor.

Abstract: A system and method for selecting between two biasing modes for biasing magneto resistive heads in a disk drive. A mode selector selects either a voltage biasing circuit or a current biasing circuit to supply the bias voltage or bias current, respectively, to a magneto resistive head. The selection can be based on changes in parameters in the disk drive or magneto resistive heads during disk drive operation.

Abstract: A write head is described having a switchable damping resistance coupled in parallel with an inductor. The damping resistance is decoupled from the inductor by rendering a transistor nonconductive when a direction of current in the inductor changes. The damping resistance is then coupled to the inductor before oscillations begin in the current in the inductor. The decoupling of the damping resistor eliminates power dissipation in the damping resistor during a change in the direction of current in the inductor.

Abstract: The present application discloses an innovative improved circuit, in which the long transient at write-to-read transitions is avoided by using a shorting switch to short the inputs of the first amplifier stage together when the read amplifier is activated. This speeds up write-to-read transition. Moreover, since read mode can now be entered more quickly after a power-down condition, this circuit also permits the use of other power-saving tricks to idle the read amplifier momentarily.

Abstract: An H-bridge for applying a current to a coil of a write head assembly for writing data to a magnetic media includes two pair of two switchable transistors. Each pair of transistors is connected between a supply voltage and a reference potential and is adapted to be connected to the coil between the transistors of each pair for turning the transistors turned on and off in a sequence to control the direction of current flow in the coil. The upper transistors of each pair serves a switching transistor, and the lower transistors provide a mirrored referenced current to the coil. A pair of capacitors are connected to a control element of a respective associated one of the lower transistors, and switching circuitry is connected to the capacitors to selectively connect each of the capacitors to inject current into the control element of the respective associated lower transistor when the respective associated lower transistor is turned on.

Abstract: A multi-head, disc drive, of a data storage system having a preamplifier that is split into a mother chip and set of daughter chips, each daughter chip corresponding to a head in the disc drive. The daughter chips contain very little circuitry, typically just a write driver, the front end of a read amplifier, a write fault detector, and a bias control circuit. Because the daughter chip contains little circuitry, it can be made much smaller and lighter than a conventional preamplifier, allowing the daughter chip to be placed on the suspension, close to the head. This allows the signal sent to and received from the head associated with a daughter chip to be strong enough not to be corrupted during transmission to the circuitry in the rest of the preamplifier. It also increases the bandwidth and reduces the power consumption of the preamplifier. The mother chip contains the remaining circuitry needed in the preamplifier and can be placed farther away, on a portion of the HSA that can support a larger chip.

Abstract: A method and apparatus, for applying a current to a coil of a write head assembly of a disk drive, or the like, to cause the flux within the coil to rapidly reverse, has an H-bridge having two pair of two switchable transistors. Each pair of the transistors is connected between a supply voltage and a reference potential, and is adapted to be connected to the coil between the two transistors of each pair. The two transistors of the first pair may be connected to receive a control signal to turn on complementary transistors of the first and second pair of transistors to selectively control current flow in the coil in first or second directions. A reference current source supplies a reference current, and one of the transistors in each of the first and second pairs of transistors is connected when turned on to mirror the reference current to control the currents in the coil.

Abstract: A read/write head in a recording and retrieval system and method of operating the read/write head are disclosed. The read/write head contains two inductive sections coupled to a switch. During a read operation, the switch is open connecting the sections in series and maximizing the inductance of the read/write head to produce a better read operation. During a write operation the switch is closed connecting the sections are in parallel to reduce the inductance of the read/write head to produce a better write operation. The switch is controlled by the R/W.sub.-- signal of the recording and retrieval system. The inductance of the inductive sections can be modified to optimize the read and write operations.

Abstract: A circuit device for selecting operating modes using a single reference pin that uses current rather than voltage in an electronic subsystem. An operating mode is selected by modulating the input bias current over a range of values. A specific range is associated with a given function so that a value of current can assume a parametric input into the subsystem. The circuit has widespread application since current can be modulated faster than voltage and it eliminates the need for multiple voltage reference points.

Abstract: An innovative disk drive system which provides a regulated bias current to a magnetoresistive read head, and controls the voltage of the magnetoresistive read head terminals so that the CENTER of the resistor is at ground. This halves the peak magnitude of the head-to-disk voltage.