Magnetic recording apparatus having circuits with differing tunnel valve sensors and about the same resistance

Patent metadata

Field	Value
Publication number	US-10014014-B1
Application number	US-201715622357-A
Country	US
Kind code	B1
Filing date	Jun 14, 2017
Priority date	Jun 14, 2017
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

An apparatus, according to one embodiment, includes a plurality of first circuits, each first circuit comprising a pair of terminals coupled to a first read transducer and a first parallel circuit. A terminal resistance of each first circuit is less than the resistance of the first read transducer thereof. A second circuit has a pair of terminals that are coupled to a second read transducer having a tunnel valve structure. An area of a tunnel barrier portion of the second read transducer is larger than an area of a tunnel barrier portion of each of the first read transducers. A resistivity of a tunnel barrier of each of the first read transducers is about the same as a resistivity of a tunnel barrier layer of the second read transducer. The terminal resistance of each first circuit is less than about five times a terminal resistance of the second circuit.

First claim

What is claimed is:

1. An apparatus, comprising:
a plurality of first circuits, each first circuit comprising a pair of terminals coupled to a first read transducer and a first parallel circuit, each first read transducer having a tunnel valve structure having a resistance, wherein a terminal resistance of each first circuit is less than the resistance of the first read transducer thereof; and
a second circuit comprising a pair of terminals coupled to a second read transducer having a tunnel valve structure;
wherein an area of a tunnel barrier portion of the second read transducer along a plane of deposition thereof is larger than an area of a tunnel barrier portion of each of the first read transducers along a plane of deposition thereof,
wherein a resistivity of a tunnel barrier of each of the first read transducers is about the same as a resistivity of a tunnel barrier layer of the second read transducer,
wherein the terminal resistance of each first circuit is less than about five times a terminal resistance of the second circuit.

2. An apparatus as recited in claim 1 , wherein the first read transducers are data readers, wherein the second read transducer is a servo reader.

3. An apparatus as recited in claim 1 , wherein the area of the tunnel barrier portion of the second read transducer is at least two times the area of the tunnel barrier portion of each first read transducer.

4. An apparatus as recited in claim 1 , wherein each first read transducer has a greater height than the second read transducer.

5. An apparatus as recited in claim 1 , wherein the first read transducers are arranged in an array, wherein the second read transducer is aligned with a longitudinal axis of the array.

6. An apparatus as recited in claim 1 , wherein each first read transducer is a first data reader, wherein the second read transducer is a second data reader.

7. An apparatus as recited in claim 1 , wherein the first and second read transducers are in a magnetic tape head.

8. An apparatus as recited in claim 1 , wherein the first parallel circuits are coupled to an exterior of a module.

9. An apparatus as recited in claim 1 , wherein the first parallel circuits are coupled directly to leads of a cable.

10. An apparatus as recited in claim 9 , wherein the first parallel circuits are coupled directly to the leads of the cable toward an end of the cable located closest to the first and second read transducers.

11. An apparatus as recited in claim 1 , wherein the first and second circuits are integrated in a module.

12. An apparatus as recited in claim 1 , wherein the first parallel circuits are located on a circuit board to which a cable is attached.

13. An apparatus as recited in claim 1 , wherein the second circuit comprises a second parallel circuit coupled to the second read transducer, wherein a resistance of the second parallel circuit is different than a resistance of each of the first parallel circuits.

14. An apparatus as recited in claim 1 , further comprising:
a drive mechanism for passing a magnetic medium over the first and second read transducers.

15. An apparatus, comprising:
a module having an array of first read transducers and a second read transducer, the first and second read transducers each having a tunnel valve structure,
wherein an area of a tunnel barrier portion of the second read transducer along a plane of deposition thereof is larger than an area of a tunnel barrier portion of each of the first read transducers along a plane of deposition thereof,
a parallel circuit coupled to each of the first read transducers;
a controller; and
a cable coupling the first and second read transducers to the controller, thereby forming a plurality of circuits extending from the controller, each circuit corresponding to one of the read transducers,
wherein a terminal resistance of each circuit corresponding to the first read transducers is less than about five times a terminal resistance of the circuit corresponding to the second read transducer.

16. An apparatus as recited in claim 15 , wherein a resistivity of a tunnel barrier portion of each of the first read transducers is about the same as a resistivity of a tunnel barrier portion of the second read transducer.

17. An apparatus as recited in claim 15 , wherein an area of the tunnel barrier portion of the second read transducer is at least two times an area of the tunnel barrier portion of each first read transducer.

18. An apparatus as recited in claim 15 , comprising a second parallel circuit coupled to the second read transducer, wherein a resistance of the second parallel circuit is different than a resistance of each of the parallel circuits coupled to the first read transducers.

19. An apparatus as recited in claim 15 , wherein the first and second read transducers are in a magnetic tape head.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Fontana Jr Robert E
• Lo Calvin S

Classifications

• G11B5/00878

  transducing different track configurations or formats on the same tape · CPC title

• G11B5/00826

  comprising a plurality of single poles or gaps or groups thereof operative at the same time · CPC title

• G11B5/4893

  relative to moving tape · CPC title

• G11B5/397

  with a plurality of independent magnetoresistive active read-out elements for respectively transducing from selected components · CPC title

• G11B5/3909 Primary

  Arrangements using a magnetic tunnel junction · CPC title