Abstract: Methods and apparatus for generating a hard drive write signal are here in disclosed. A disclosed method comprises generating a hard drive write signal on an output of a switch based on an edge of the first control signal and reducing the hard drive write signal based on an edge of a second control signal via a second switch.

Abstract: A write current circuit (300, 400) adapted to drive a thin film write head (202) of a mass media information storage device. The write current circuit (300, 400) further includes programming circuitry (311, 411) driven such that parameters of the write current waveform can be varied, including the write current overshoot amplitude and/or overshoot duration. The present invention achieves technical advantages by providing the ability to program out or adjust for system introduced asymmetries in the write current waveform.

Abstract: A jewelry piece comprising strands made from connected links wherein complementary strands may be interconnected to form double strands or larger strands consisting of multiple interconnected single strands.

Abstract: One embodiment of the invention includes a driver circuit. The driver circuit comprises a high-side switch that is activated in response to a positive driver input signal to provide a positive output signal at a driver output. The driver circuit also comprises a low-side switch that is activated in response to a negative driver input signal to provide a negative output signal at the driver output. The positive and negative driver input and output signals can be relative to respective cross-over magnitudes. The driver circuit further comprises at least one impedance-matching device configured to activate the low-side switch in response to a positive signal reflection at the driver output and to activate the high-side switch in response to a negative signal reflection at the driver output.

Abstract: Methods and apparatus for generating a hard drive write signal are here in disclosed. A disclosed method comprises generating a hard drive write signal on an output of a switch based on an edge of the first control signal and reducing the hard drive write signal based on an edge of a second control signal via a second switch.

Abstract: A circuit (40) for use in a mass data storage device (10) has first (44) second (46) current driver circuits for providing write currents to the data transducer (18). The first and second current levels are different, the second current level being lower than the first. The first current driver circuit (44) may be used to apply currents representing user data to the data transducer (18) and the second current driver circuit (46) may be used to apply currents representing servo information to the data transducer (18). In addition, the first (44) and second (46) current drivers circuits may be operated at different frequencies. The first (44) and second (46) current driver circuits additionally may share at least some circuit components (70, 72, 74-75, 64-65), and may operate at different write speeds.

Abstract: The present invention covers circuits to achieve high data rate writing.

Abstract: A voltage-mode boosting write driver circuit (40) having a pair of voltage boosting PMOS transistor sets (44, 46) coupled to a high current H-switch (42). One set (44) of the boosting PMOS transistors correspondingly pulls output pin HY high, while the other transistor set (46) correspondingly pulls output pin HX high and the other output pin HY low thereby significantly improving the head voltage swing, and also achieving a faster slew rate. Moreover, resistors (R3, R4) of the H-switch are both matched to each other and impedance matched to a flex cable (T0) interconnection impedance, which interconnection is coupled to the thin film head, to thereby eliminate signal reflection such that the write current (Iw) settles quickly with minimum ringing to achieve a high data rate. Moreover, less power dissipation and smaller number of devices used are achieved by making use of existing transient currents of the pre-driver emitter follower stage.

Abstract: A circuit (40) for use in a mass data storage device (10) has first (44) second (46) current driver circuits for providing write currents to the data transducer (18). The first and second current levels are different, the second current level being lower than the first. The first current driver circuit (44) may be used to apply currents representing user data to the data transducer (18) and the second current driver circuit (46) may be used to apply currents representing servo information to the data transducer (18). In addition, the first (44) and second (46) current drivers circuits may be operated at different frequencies. The first (44) and second (46) current driver circuits additionally may share at least some circuit components (70, 72, 74-75, 64-65), and may operate at different write speeds.

Abstract: A write current circuit (40) adapted to drive a thin film write head (L0) of a mass media information storage device. The write current circuit includes a write current reference voltage circuit (42) adapted to selectively establish amplitude of a write current signal. The write current circuit further includes programming circuitry (M5-M10) driven such that several parameters of the write current waveform can be controlled, including the write current amplitude, overshoot amplitude and overshoot duration. The present invention achieves technical advantages by providing the ability to both produce an accurate write current, and also providing the ability to establish the write current waveform shape so that customers can optimize disk drive performance even when using different thin film write heads available from different suppliers.

Abstract: A write drive circuit (40) for a hard disk drive selectively providing a current mode operation for high speed data write of a single channel, and selectively providing a voltage mode operation during a servo write operation. A central buffer has a first circuit (50) providing a current mode drive signal to a head during a single channel write operation, and a second circuit (52) providing a voltage mode drive signal for multi-channel servo write operation. The outputs of both circuits (50, 52) is provided over a common differential connection (T1) feeding a pre-driver circuit (70) adapted to drive one or many heads, as determined by head select control lines (72). The circuit provides >1.6 Gb/s data write speed in single channel write operation, and has an architecture utilizing only two signal lines for four channels.

Abstract: A write drive circuit (40) for a hard disk drive selectively providing a current mode operation for high speed data write of a single channel, and selectively providing a voltage mode operation during a servo write operation. A central buffer has a first circuit (50) providing a current mode drive signal to a head during a single channel write operation, and a second circuit (52) providing a voltage mode drive signal for multi-channel servo write operation. The outputs of both circuits (50, 52) is provided over a common differential connection (T1) feeding a pre-driver circuit (70) adapted to drive one or many heads, as determined by head select control lines (72). The circuit provides >1.6 Gb/s data write speed in single channel write operation, and has an architecture utilizing only two signal lines for four channels.

Abstract: A write current circuit (40) adapted to drive a thin film write head (L0) of a mass media information storage device. The write current circuit includes a write current reference voltage circuit (42) adapted to selectively establish amplitude of a write current signal. The write current circuit further includes programming circuitry (M5-M10) driven such that several parameters of the write current waveform can be controlled, including the write current amplitude, overshoot amplitude and overshoot duration. The present invention achieves technical advantages by providing the ability to both produce an accurate write current, and also providing the ability to establish the write current waveform shape so that customers can optimize disk drive performance even when using different thin film write heads available from different suppliers.

Abstract: A voltage-mode boosting write driver circuit (40) having a pair of voltage boosting PMOS transistor sets (44, 46) coupled to a high current H-switch (42). One set (44) of the boosting PMOS transistors correspondingly pulls output pin HY high, while the other transistor set (46) correspondingly pulls output pin HX high and the other output pin HY low thereby significantly improving the head voltage swing, and also achieving a faster slew rate. Moreover, resistors (R3, R4) of the H-switch are both matched to each other and impedance matched to a flex cable (T0) interconnection impedance, which interconnection is coupled to the thin film head, to thereby eliminate signal reflection such that the write current (Iw) settles quickly with minimum ringing to achieve a high data rate. Moreover, less power dissipation and smaller number of devices used are achieved by making use of existing transient currents of the pre-driver emitter follower stage.

Abstract: The present invention covers circuits to achieve high data rate writing on thin film transducer. The circuit comprises an ECL pre-driver adapted for driving a high current H-switch driver driving a write head, such as for a hard disk drive (HDD) circuit (10). Preferably, the pre-driver (16) includes emitter-follower transistors (Q8-Q13) and resisters (R8-R12), configured in three stages of an emitter-follower buffer. This ECL level pre-driver is used to build enough current and voltage drive capability to drive the high-current H-switch driver. Three pairs of PMOS transistors (M5-M10) are configured to switch in the pseudo ECL level logic swing. One pair of transistors is used to switch the right data signal, while another set of transistors is used to switch a pulsing signal to create a write current overshoot. A third set of transistors are used to switch the pulsing signal in the other direction.