Disk Drive with Preamplifier for Multiple Readers in a Slider with a Common Return Signal

Abstract

Disk drive embodiments with common lead connections in the slider, suspension, and preamplifier are described. The arm electronics IC includes a preamplifier with single-ended input from the set of signal traces that include a common signal return lead for the plurality of read transducers (readers) in the slider. Two embodiments of the preamps are described that include a single-ended design and a pseudo-single-ended design. Each embodiment supplies the required bias to each read transducer using an operational transconductance amplifier (OTA) that drives a variable current source connected to the transducer. The positive input to the OTA is a DC voltage with the AC signal from the transducer imposed on it. The negative input is a DC reference voltage. Various embodiments of the signal trace configuration on the suspension are described including a single and double layer embodiments.

Description

RELATED APPLICATIONS [0001]This application is related to provisional application 61 / 879,544, which was filed on Sep. 18, 2013 and the benefit of which is hereby claimed for the present application. A related application is titled INTEGRATED LEAD SUSPENSION (ILS) FOR TWO-DIMENSIONAL MAGNETIC RECORDING (TDMR) DISK DRIVE filed Jul. 25, 2014, bearing Ser. No. 14 / 340,690.FIELD OF THE INVENTION[0002]The present invention relates to the field of magnetic disk drive design and more particularly to the design and interconnection of sliders, suspensions for sliders and signal amplifiers and more particularly to the design and interconnection of such components in a system having a plurality of read heads (readers) in a slider.BACKGROUND [0003]A disk drive system includes at least one magnetic disk, read / write heads, and a suspension which supports a slider with the magnetic read / write heads and provides electrical connections to the system electronics. FIG. 1 is an illustration of selected c...

AI Technical Summary

Benefits of technology

The invention relates to a system for connecting and biasing read transducers in a disk drive. The system uses a common lead system that reduces the area required for interconnects in the slider, suspension, and preamplifier. The preamplifier includes a single-ended or pseudo-single-ended design, which drives a variable current source connected to the read transducer using an operational transconductance amplifier. The system also includes signal trace configurations on the suspension that involve interleaving a common return lead with dedicated signal traces or using a shielding network. The technical effects of the invention include a reduction in interconnect layout area, improved signal quality, and reduced noise.

Problems solved by technology

There is significant physical separation between the transducers, which leads to skew in relation to the tracks on the disk.

There is limited room for these electrical paths between the slider and the preamplifier.

Each trace path has a cost associated with it.

In addition, having three separate independent readers requires additional space between read transducers inside the slider.

Having additional distance between read transducers creates skew problems caused by physical distance between the transducers.

The fly-height control between transducers also creates spacing control problems due to the additional distance between transducers.

For the suspension interconnection, having six conductive traces creates area issues in the layout, where the suspension's tail width space is limited.

For the preamplifier, having IDAs requires additional IC area and power, which are key design constraints for the electronic packaging (flex area and mechanical connection to actuator).

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