EP-4738355-A1 - SWITCHABLE INDUCTOR FOR BOOST OR MATCHING OPTIMIZATION

Abstract

A module including first and second variable inductances. The first variable inductance is electrically connected to a pair of nodes in a first half-circuit. One of the nodes in the first half-circuit is a first connection terminal. The second variable inductance is electrically connected to a pair of nodes in a second half-circuit. One of the nodes in the second half-circuit is a second connection terminal. The first half-circuit receives a flow of current in response to the second half-circuit supplying the current to the load in a flow direction from a load through the first connection terminal. The second half-circuit is configured to receive the flow of the current in response to the first half-circuit supplying the current to the load in a direction opposite to the flow direction from the load through the second connection terminal.

Inventors

• Brenden, Jason Paul
• HUA, JUNQI
• RABE, CAMERON CARROLL
• GLEASON, JEFFREY A.
• MAZUR, PAUL MARK

Assignees

• Avago Technologies International Sales Pte. Limited

Dates

Publication Date

20260506

Application Date

20251029

Claims (15)

1. A module comprising: a first variable inductance electrically connected to a pair of nodes in a first half-circuit, one of the nodes in the first half-circuit being a first connection terminal; and a second variable inductance electrically connected to a pair of nodes in a second half-circuit, one of the nodes in the second half-circuit being a second connection terminal, wherein the first half-circuit is configured to receive, from a load through the first connection terminal, a flow of current in response to the second half-circuit supplying the current to the load in a flow direction, wherein the second half-circuit is configured to receive, from the load through the second connection terminal, the flow of the current in response to the first half-circuit supplying the current to the load in a direction opposite to the flow direction.
2. The module according to claim 1, wherein the load is a read/write head in a hard disc drive.
3. The module according to claim 1 or 2, wherein the first connection terminal and the second connection terminal are configured to electrically connect the load between the first connection terminal and the second connection terminal.
4. The module according to claim 1 or 2, wherein the first connection terminal and the second connection terminal are configured to electrically connect the load in series with the first connection terminal and the second connection terminal.
5. The module according to any one of the claims 1 to 4, wherein the first variable inductance is electrically connected directly to the first connection terminal.
6. The module according to any one of the claims 1 to 4, wherein the first variable inductance is between the pair of nodes in the first half-circuit.
7. The module according to any one of the claims 1 to 6, wherein the second variable inductance is electrically connected directly to the second connection terminal.
8. The module according to any one of the claims 1 to 6, wherein the second variable inductance is between the pair of nodes in the second half-circuit.
9. The module according to any one of the claims 1 to 8, wherein the module comprises the first half-circuit.
10. The module according to any one of the claims 1 to 9, wherein the first half-circuit comprises the first variable inductance.
11. The module according to any one of the claims 1 to 10, wherein the module comprises the second half-circuit.
12. The module according to any one of the claims 1 to 11, wherein the second half-circuit comprises the second variable inductance.
13. The module according to any one of the claims 1 to 12, wherein the first variable inductance comprises an inductor in parallel with a switch; wherein in particular the switch and another switch are electrically connected to a center tap of the inductor.
14. The module according to any one of the claims 1 to 13, wherein the second variable inductance comprises an inductor in parallel with a switch; wherein in particular the switch and another switch are electrically connected to a center tap of the inductor.
15. The module according to any one of the claims 1 to 14, wherein the first half-circuit comprises: a current source configured to supply a portion of the current to the first connection terminal; wherein in particular the module comprises at least one of the following features (A) and (B): (A) the first half-circuit further comprises another current source configured to supply another portion of the current to another of the nodes in the first half-circuit; and (B) the second half-circuit comprises a current source configured to supply a portion of the current to the second connection terminal, wherein in particular the second half-circuit further comprises another current source configured to supply another portion of the current to another of the nodes in the second half-circuit.

Description

BACKGROUND Hard disk drive (HDD) write drivers are electronic circuits responsible for converting digital data into current during the recording of data. An HDD write driver can control the current sent to a write head of a disk drive. Magnetic signals resulting from the current are written onto disk platters by the write head during the data recording. BRIEF DESCRIPTION OF DRAWINGS The accompanying drawings, which are incorporated in and form a part of this specification, illustrate examples of the disclosure and, together with the description, explain principles of the examples. FIG. 1 illustrates an exemplary assembly, in accordance with one or more embodiments of the disclosure.FIG. 2 illustrates an exemplary module, in accordance with one or more embodiments of the disclosure.FIG. 3 illustrates exemplary variable inductances, in accordance with one or more embodiments of the disclosure.FIG. 4 illustrates exemplary variable inductances, in accordance with one or more embodiments of the disclosure.FIG. 5 illustrates an exemplary half-circuit, in accordance with one or more embodiments of the disclosure.FIG. 6 illustrates an exemplary half-circuit, in accordance with one or more embodiments of the disclosure.FIG. 7 illustrates an exemplary assembly, in accordance with one or more embodiments of the disclosure.FIG. 8 illustrates an exemplary half-circuit, in accordance with one or more embodiments of the disclosure.FIG. 9 illustrates an exemplary half-circuit, in accordance with one or more embodiments of the disclosure.FIG. 10 illustrates exemplary variable inductances, in accordance with one or more embodiments of the disclosure.FIG. 11 illustrates an exemplary switch, in accordance with one or more embodiments of the disclosure. In the drawings, like reference symbols and numerals indicate the same or similar components. Like elements in the various figures are denoted by like reference symbols and numerals for consistency. Unless otherwise indicated, like elements and method steps are referred to with like reference numerals. DETAILED DESCRIPTION OF THE INVENTION The following describes technical solutions in this specification with reference to the accompanying drawings. Exemplary embodiments are described in detail with reference to the accompanying drawings. The terminology used herein is for describing various examples only, and is not to be used to limit the disclosure. Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains and after an understanding of the disclosure of this application. Terms, such as those defined in commonly used dictionaries, are to be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the disclosure of this application. Although the present technology has been described by referring to certain examples, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the discussion. As data rates continue to increase, it is more important to have good high frequency impedance matching as well as fast rise times in HDD write drivers. Because the data spans a large range of frequencies, it is desirable to get good impedance matching across a broad range of frequencies. Most of the parasitic capacitance on the driver circuit is contributed by the driver devices, usually made out of large bipolar transistors. Accordingly, there is a need in the art for an improved write driver. Referring to FIG. 1, assembly 100 is illustrated. Assembly 100 may include module 110, power supply 120, flexible circuit tline 130 and load 140. Those skilled in the art will appreciate there may be additional components in assembly 100. Power supply 120 may convert power from an external power source into supply voltages VCC and VEE. Power supply 120 may output, to module 110, supply voltage VCC at a positive direct current (DC) voltage and supply voltage VEE at a constant negative DC voltage despite any fluctuation in load conditions on module 110 caused by tline 130 and load 140. Tline 130 may be implemented as a group of individual cables or wires that are bound together. Tline 130 may comprise multiple strands of wires. In some implementations, tline 130 may be a flexible interconnect cable. Load 140 is an impedance that module 110 may happen to be driving. For example, load 140 may be an electronic component, an electronic circuit, an electronic device, and/or any device that consumes electrical power. In some implementations, load 140 may be a read/write head in a hard disc drive. Referring to FIG. 2, module 110 is illustrated. Module 110 may be implemented as a pre-driver, a pre-amplifier, a pre-stage driver, a signal conditioner, an intermediate driver, and/or any other electronic circuitry that may condition or amplify current on lin